N-heterocyclic carbene adsorption states on Pt(111) and Ru(0001).

N-heterocyclic carbene ligands (NHCs) are increasingly used to tune the properties of metal surfaces. The generally greater chemical and thermal robustness of NHCs on gold, as compared to thiolate surface ligands, underscores their potential for a range of applications. While much is now known about the adsorption geometry, overlayer structure, dynamics, and stability of NHCs on coinage elements, especially gold and copper, much less is known about their interaction with the surfaces of Pt-group metals, despite the importance of such metals in catalysis and electrochemistry. In this study, reflection absorption infrared spectroscopy (RAIRS) is used to probe the structure of benzimidazolylidene NHC ligands on Pt(111) and Ru(0001). The experiments exploit the intense absorption peaks of a CF3 substituent on the phenyl ring of the NHC backbone to provide unprecedented insight into adsorption geometry and chemical stability. The results also permit comparison with literature data for NHC ligands on Au(111) and to DFT predictions for NHCs on Pt(111) and Ru(0001), thereby greatly extending the known surface chemistry of NHCs and providing much needed molecular information for the design of metal-organic hybrid materials involving strongly reactive metals.

Availability of Physical Activity Tracking Data from Wearable Devices for Glaucoma Patients.

Physical activity has been found to potentially modulate glaucoma risk, but the evidence remains inconclusive. The increasing use of wearable physical activity trackers may provide longitudinal and granular data suitable to address this issue, but little is known regarding the characteristics and availability of these data sources. We performed a scoping review and query of data sources on the availability of wearable physical activity data for glaucoma patients. Literature databases (PubMed and MEDLINE) were reviewed with search terms consisting of those related to physical activity trackers and those related to glaucoma, and we evaluated results at the intersection of these two groups. Biomedical databases were also reviewed, for which we completed database queries. We identified eight data sources containing physical activity tracking data for glaucoma, with two being large national databases (UK BioBank and All of Us) and six from individual journal articles providing participant-level information. The number of glaucoma patients with physical activity tracking data available, types of glaucoma-related data, fitness devices utilized, and diversity of participants varied across all sources. Overall, there were limited analyses of these data, suggesting the need for additional research to further investigate how physical activity may alter glaucoma risk.

Diabetes in India's North East Study: Prevailing Insulin Usage and Insulin Injection Practices amongst Type 2 Diabetes Mellitus Patients.

OBJECTIVE: Insulin therapy is mostly advised in patients with poorly controlled type 2 diabetes mellitus (T2DM). However, wide variation exists in insulin practice and usage across the Indian geography. MATERIALS AND METHODS: In this cross-sectional study, a retrospective audit of the medical records of T2DM patients who were receiving insulin and attending an urban referral clinic in Northeast India during the period from 2006 to 2017 was conducted to analyze the insulin utilization pattern and injection technique variation. A total of 1,454 patients were included, 60% were male and 40% were female. RESULTS: At presentation, the mean duration of T2DM was 12.13 (7.45) years. Insulin with or without oral anti-diabetic (OADs) was received by 52.27% and 47.73% of patients, respectively. The majority (62.93%) used a pen device for insulin administration. The patient-reported reasons for insulin therapy initiation were OAD failure (33.15%), glucotoxicity (30.26%) and diabetesassociated complications (20.36%). The mean ± standard deviation (SD) total daily dose (TDD) of insulin was 33.05 ± 17.09 (0.53 ± 0.30 units/kg/day). The breakup for the number of injection(s) per day was one (234,16.09%), two (970,66.71%), three (166,11.42%), four (78, 5.36%), and five (6, 0.41%). The majority (67.88%) used premixed insulin, while 10.90% used basal insulin alone. Compared to those without lipohypertrophy (LH), patients with LH were less likely to rotate the site of injection (0.85 vs 17.90%; p = 0.000), space the injections (10.71 vs 23.91%; p = 0.000), injected less often in correct site (7.81 vs 29.0%; p = 0.000), more likely to use wrong angles (10.08 vs 22.73%; p = 0.000) and reuse the needles (5.63 vs 14.86%; p = 0.000). Also, 34.87% of patients were not storing their insulin device at the right temperature and 8.87% experienced at least one episode of a hypoglycemic event. CONCLUSION: This audit depicts important attributes of current injection practices amongst T2DM patients on insulin and suggests the possible benefits of adopting correct practices for avoiding complications such as LH and hypoglycemia.

Critical Appraisal of Drug Promotional Literature in Accordance With WHO Guidelines.

Background Drug promotional literature (DPL) is used as a marketing tactic to publicize the introduction of new medications. As drug companies are promoting the literature for their brand products, bias is possible. Various studies have demonstrated that printed DPLs disseminated by pharmaceutical companies are typically skewed. Material and method A prospective, observational study was carried out in the outpatient departments of a tertiary care hospital to analyze the DPL of different pharmaceutical companies using WHO criteria for "Ethical criteria for medicinal drug promotion, 1988". Results Out of 192 DPLs analyzed, information regarding the generic name, brand name, amount of active ingredient, and manufacturer name was found in all the DPLs (100%). Though therapeutic uses were mentioned in 91% of DPLs, dosage schedule (regimen) was mentioned only in 60%. Drug safety information such as the side effects and significant adverse drug reactions, precautions and warnings, contraindications, and major drug interactions were present in 24%, 36%, and 20%, respectively. Address of the manufacturer and reference to scientific literature were present only in 63% and 53% of DPLs, respectively. References mainly were from journals, present in 71% of DPLs. Most of the claims made in DPLs were regarding efficacy (73%), followed by safety (34%).  Conclusion In our study, not a single DPL fulfilled all the nine WHO criteria. A doctor should rigorously evaluate study findings before prescribing because misleading and incorrect information is now frequently found in this literature.

Nature's Gold (Moringa Oleifera): Miracle Properties.

Moringa oleifera, known as a miracle tree, is a small plant cultivated all over the world due to its multiple medicinal uses.It is cultivated for its nutritious pods, edible leaves, and flowers which are very helpful as food, medicine, cosmetic oil, and forage for livestock. It is a good source of protein, oils, vitamins, fatty acids, micro-macro mineral elements, and various phenolics. Its roots, bark, gum, leaf, fruit (pods), flowers, seed, and seed oil possess various biological activities. The main flavonoids found in its leaves are myricetin, quercetin, and kaempferol. Each part of the Moringa oleifera tree is used for a variety of nutritional and medicinal purposes. The tree has anti-inflammatory, antimicrobial, antioxidant, anticancer, antihypertensive, hepatoprotective, anti-ulcer, antifertility, and diuretic properties. Its many pharmacological benefits are exploited as therapeutic remedies in the traditional medicinal system for various diseases. Moringa's hypolipidemic, antihypertensive, antioxidant, anti-cancer, anti-diabetic, and hepatoprotective properties have been attributed to quercetin, phenolic acid, tannins, and saponins. More research into this remarkable healer could lead to the creation of new drugs to treat a variety of illnesses. This article gives a quick summary of the medical potential of Moringa and its future as a component of modern medicine. According to the findings of this study, Moringa needs to be properly evaluated before it can be used as a medication in modern medicine.

Effect on Reaction Time in Primary Hypothyroid Patients Before and After Thyroxin Treatment.

Introduction Thyroid hormones play a crucial role in the proper functioning of the nervous system. Both T3 and T4 hormones have many significant actions on the neuromuscular system and brain. In hypothyroid patients, various neurological signs and symptoms such as weakness, fatigue, paresthesias, arthralgias, etc. may be seen. Reaction time is a good indicator of the processing of the central nervous system. So, our study aims to observe the change in reaction time in hypothyroid patients as compared to the control group. And to understand, if some difference is observed, how does it change after treatment with thyroxin in a hypothyroid group. Materials and methods This study was conducted at the tertiary care teaching hospital in the Vidarbha region. In this study, 40 newly diagnosed primary hypothyroid patients (including males and females), in the age group of 20 to 45 years, and whose thyroid-stimulating hormone (TSH) levels were between 10 and 50 mIU/L and free T4 levels below the normal level were included. A suitable comparable control group of the same demographic parameter was selected. Reaction time was taken before the start of thyroxin treatment in both groups, and results were analyzed by using an unpaired t-test. The reaction time of the hypothyroid group was again measured after eight weeks of the start of thyroxin treatment, it was compared with the initial reaction time, and data were compared by using the paired t-test. Result In the hypothyroid group as compared to the control group both auditory and visual reaction times were significantly on the higher side (p<0.05). Also, there was a significant improvement in reaction time after the start of thyroxin treatment (p<0.05), which suggests improvement in CNS activity in hypothyroid patients after initiation of therapy. Conclusion Thyroid hormones play a crucial role in the proper functioning and processing of the central nervous system. Due to this reason, reaction time in hypothyroid patients was on the longer side, showing a slowing of the nervous system when reacting to a specific stimulus. After thyroxin treatment for a sufficient period, reaction times were of shorter duration as compared to before the start of thyroxin, which shows well-recovered nervous activity. Therefore, reaction time is not only used as a handy tool to identify early central nervous system manifestations of hypothyroidism but also used to monitor response to treatment.

Assessing Usability of Smartwatch Digital Health Devices for Home Blood Pressure Monitoring among Glaucoma Patients.

Glaucoma is a leading cause of blindness worldwide. Blood pressure (BP) dysregulation is a known risk factor, and home-based BP monitoring is increasingly used, but the usability of digital health devices to measure BP among glaucoma patients is not well studied. There may be particular usability challenges among this group, given that glaucoma disproportionately affects the elderly and can cause visual impairment. Therefore, the goal of this mixed-methods study was to assess the usability of a smart watch digital health device for home BP monitoring among glaucoma patients. Adult participants were recruited and given a smartwatch blood pressure monitor for at-home use. The eHEALS questionnaire was used to determine baseline digital health literacy. After a week of use, participants assessed the usability of the BP monitor and related mobile app using the Post-study System Usability Questionnaire (PSSUQ) and the System Usability Scale (SUS), standardized instruments to measure usability in health information technology interventions. Variations in scores were evaluated using ANOVA and open-ended responses about participants' experience were analyzed thematically. Overall, usability scores corresponded to the 80th-84th percentile, although older patients endorsed significantly worse usability based on quantitative scores and additionally provided qualitative feedback describing some difficulty using the device. Usability for older patients should be considered in the design of digital health devices for glaucoma given their disproportionate burden of disease and challenges in navigating digital health technologies, although the overall high usability scores for the device demonstrates promise for future clinical applications in glaucoma risk stratification.

Fluorescence Enhancement Based Quantification of Human Serum Albumin from Biological Sample Using Indole Based Nanosuspension: Molecular Interactions and Molecular Docking Studies.

Fluorescent 3-[(E)-(2-phenylhydrazinylidene) methyl]-1H-indole (PHI) was synthesized by condensation of indole-3-carboxaldehyde and phenyl hydrazine in presence of acetic acid and ethanol and after spectral characterization used further to prepare its aqueous nano suspension by reprecipitation method using polyvinylpyrrolidone (PVP) as stabilizer. The average particle size of nano suspension measured by Dynamic Light Scattering (DLS) was found 77.5 nm while FESEM microphotograph showed spherical morphology. The blue shift in the absorption spectrum and stokes shifted fluorescence of nanosuspension of PHI compared to its monomer spectrum in dilute solution indicate formation of H-type aggregate by face to face overlapping of the molecules.The aggregation induced enhanced emission (AIEE) of PVP capped nanosuspension of PHI is increased appreciably by presence of aqueous solution of human serum albumin (HSA). A suitable mechanism of molecular binding interactions based on complex formation between PHI nanoaggregate and HSA through PVP is proposed. Fluorescence life time, zeta potential and particle size data of PHI nanoparticles (PHINPs) obtained in presence of different amounts of HSA are in support of molecular interactions leading to complex formation. The molecular docking studies showed that HSA and PVP capped PHINPs exhibit strong hydrogen bonding interaction. The fluorescence enhancement effect induced in PHI nanosuspension is used further to develop analytical method for quantitative estimation of HSA in aqueous biological sample solution.

Impact of Anti-Diabetic Medications on Quality of Life in Persons with Type 2 Diabetes Mellitus.

Introduction: Type 2 diabetes mellitus (T2DM) has been found to be associated with poor quality of life (QOL). The aim of this study was to measure QOL in T2DM patients and examine if the patients' socio demographic, diabetes-related clinical characteristics and insulin usage are associated with better quality of life. Materials and Methods: This clinic based cross-sectional study analyzed data from outpatients with T2DM attending a referral clinic between January and June 2016. Association between Diabetes Attitudes, Wishes and Needs (DAWN) QOL and few demographic, socioeconomic, clinical and biochemical predictors were examined using multivariate logistic regression model. A total of 518 patients completed the interview. Results: The HbA1c level of insulin ± oral anti-diabetic (OAD) cohort was significantly lower (7.89 ± 1.98) than the OAD cohort (8.79 ± 1.96), P < 0.001. Compared to their counterparts in the OAD cohort, patients on insulin were older with longer duration of diabetes mellitus. Co-morbid confounders like obesity, hypoglycemia, and blood pressure control or socio demographic confounders like income, education were almost similar in both the cohorts. The incidence of hypertension, coronary artery disease (CAD) and statin usage was significantly higher in the insulin cohort. The overall composite DAWN QOL scores of the insulin ± OAD cohort (25.42 ± 4.35) was marginally higher than that of the OAD cohort (23.62 ± 5.06) (P = 0.067). Analog insulin users were also found to have significantly higher composite DAWN QOL scores compared to human insulin users (25.77 ± 5.73 vs.24.13 ± 4.88, P = 0.037). Conclusions: The insulin cohort, despite being older and having longer duration of diabetes, had significantly higher diet compliance score, and enhanced QOL owing to better diabetes-related knowledge and treatment adherence characteristics than non-insulin users. Questionnaires-based evaluation of QOL can provide better understanding of the patient's experience of the illness, self-care, psychological and emotional functioning, and choice of therapeutic modality enhancing the quality of care.

Patent landscape for discovery of promising acyltransferase DGAT and MGAT inhibitors.

INTRODUCTION: DGAT and MGAT enzymes play an important role in triacylglycerol (TGA) biosynthesis. Overexpression of these enzymes may lead to accumulation of TGA in adipose tissues causing development of diseases such as obesity and diabetes. High triglyceride levels increase risk factors for atherosclerosis, and increase the risk of heart attack, stroke and other heart diseases. DGAT and MGAT inhibitors are used for the treatment of such metabolic diseases. A number of DGAT and MGAT inhibitors entered into clinical and preclinical stages. However, some adverse effects are associated with them. Thus there is need to develop new, potent and safe DGAT and MGAT inhibitors. AREA COVERED: In this review, the authors carefully searched patent literature and reviewed recent advances since the year 2014. Diverse chemical classes reported in the patents belonging to the category DGAT and MGAT inhibitors have been highlighted. EXPERT OPINION: DGAT and MGAT inhibitors are now gaining significant importance in the treatment of metabolic diseases. Fused heterocycles with a combination of aromatic and aliphatic hydrophobic substituents could offer more potent DGAT and MGAT inhibitors. Previously reported chemical scaffolds and their DGAT and MGAT inhibitory activity could be employed as an input for some in silico studies to discover novel, potent and safe DGAT and MGAT inhibitors.

FRET Between Riboflavin and 9-Anthraldehyde Based Fluorescent Organic Nanoparticles Possessing Antibacterial Activity.

The aqueous suspension of fluorescent nanoparticles were prepared by using 9-anthradehdye derivative (AH). The nanoparticles (AHNPs) were characterized using DLS-zeta sizer and SEM techniques. The photo physical properties of nanoparticles and precursor were measured and compared using UV-absorption spectroscopy, fluorescence spectroscopy and fluorescence lifetime studies. The significant overlap between fluorescence spectrum of AHNPs and excitation spectrum of Riboflavin (RF) led us to explore Fluorescence Resonance Energy Transfer (FRET) studies between AHNPs and RF in aqueous medium. The mechanism of FRET from AHNPs to RF discussed on spectral observations, thermodynamic parameters and changes produces in fluorescence lifetime in absence and presence of different concentrations of RF to AHNPs. The limit of detection for RF (0.071 µM) is considerably low compared with reported methods. Thus, we explore AHNPs as novel nano probe for quantitative determination of RF in pharmaceutical samples based on FRET study. In addition with this, AHNPs has excellent antibacterial activity than the bulk material for two different bacteria culture viz. E. coli and Bacillus sps. Graphical Abstract 9-anthradehdye based fluorescent nanoparticles (AHNPs) explores as nano probe to detect Riboflavin (RF) in aqueous medium based on Fluorescence Resonance Energy Transfer (FRET) studies. The proposed analytical method successfully applied for quantitative determination of RF in pharmaceutical samples. In addition, with this, AHNPs has excellent antibacterial activity than the bulk material for two different bacteria culture suspension viz. E. coli and Bacillus sps.

Carbazole based nanoprobe for selective recognition of Fe3+ ion in aqueous medium: Spectroscopic insight.

A simple carbazole based nanoprobe prepared by reprecipitation method shows selective sensing behavior for Fe3+ ion in aqueous medium. The prepared SDS capped 9-phenyl carbazole nanoparticles (9-PCzNPs) has narrower particle size distribution with an average diameter 35nm and zeta potential of -34.3mV predicted a good stability with negative surface charge over the nanoparticles. The Field Emission Scanning Electron Microscopy (FE-SEM) image showed cubic shape morphology of nanoparticles. The aqueous suspension of SDS capped 9-phenyl carbazole nanoparticles exhibited aggregation induced enhanced red shifted intense emission in comparison with the emission arising from dilute solution of 9-phenyl carbazole in DCM. The cation recognition test based on fluorescence change shows Fe3+ ion induce significant fluorescence quenching, however remaining cations responds negligibly. The obtained quenching data fit into Stern-Volmer relation in the concentration range of 0.0-1.0µg·mL-1 of Fe3+ ion solution and the detection limit is 0.0811µg·mL-1. The probable mechanism of fluorescence quenching of SDS capped 9-PCzNPs is because of adsorption of Fe3+ ion over the negatively charged surface of NPs through electrostatic interaction. Thus the proposed method was successfully applied for the detection of Fe3+ ion in environmental water sample.

Alternate-day dosing of linagliptin in type 2 diabetes patients controlled on once daily dose: A case series.

Linagliptin, a dipeptidyl peptidase 4 (DPP 4) inhibitor with a long terminal half life, significantly inhibits the DPP 4 enzyme at a steady state up to 48 h after the last dose. The present case series examined the hypothesis that linagliptin retains its efficacy during alternate day dosing in type 2 diabetes patients when switched over from once daily (OD) dosing. Eight type 2 diabetes patients maintaining stable glycosylated hemoglobin (HbA1c) with acceptable fasting plasma glucose and postprandial glucose levels and receiving linagliptin 5 mg OD for at least 6 weeks, with a stable dose of concomitant antidiabetic medications were given linagliptin 5 mg every alternate day. The median HbA1c while on the OD regimen was 6.1% (43 mmol/mol) (range: 5.8-6.9% [40-52 mmol/mol]) and median duration of diabetes was 7 years (range: 0.75-16 years). After a median follow-up period of 21weeks,the glycemic control was maintained in all patients similar to their baseline values (median HbA1c: 6.0% [42 mmol/mol], range: 5.1-7.1% [32-54 mmol/mol]). The body weight, fasting, and random glucose levels at baseline were also well maintained at the end of treatment. Optimal glycemic status maintained in our study population favors our hypothesis that linagliptin used alternate daily after switching from initial OD dose of the drug in patients on a stable background antidiabetic medications retains its efficacy. Paradoxically, alternate day dosing may affect compliance if the patient forgets when they took the last dose. Further studies including larger cohorts are needed to validate this finding and identify patients who can benefit from the alternate day regimen.

Molecular Typing of Bluetongue Viruses Isolated Over a Decade in South India.

Bluetongue (BT) is an arthropod-borne viral disease mostly of sheep. Bluetongue virus (BTV) is a segmented double-stranded RNA virus belonging to the genus Orbivirus of family Reoviridae and is transmitted by midges belonging to Culicoides spp. The disease is endemic in the tropics and subtropics, and the incidence is high in southern India. Twenty-six serotypes of BTV have been reported worldwide. Although most of the serotypes have been reported in India, information regarding currently circulating serotypes is essential to develop control programs. Both serological assays and nucleic acid-based assays have been used for typing BTV. Segment 2, which codes for the outer capsid protein VP2, is the target for PCR-based typing; however, the VP2 sequence diversity among viruses belonging to the same serotype but isolated from different geographical areas makes it essential to develop geographical based reagents. In this study, reverse transcription PCR was developed based on sequences of Indian isolates of BTV (serotypes 1, 2, 9, 10, 12, 16, 21 and 23), and this was applied to type 52 isolates obtained during the last decade. It was found that multiple serotypes circulate, with involvement of more than one serotype infecting individual animals and herds over a period in a given area. Detection of circulating serotypes and estimation of herd immunity against different serotypes of BTV may provide important information for predicting the distribution of these serotypes and inclusion of serotypes in vaccines.

Assessment of the Risk Factors for Oro-Dental Injuries to Occur during General Anesthesia and Measures taken by Anesthesiologist to Prevent them.

BACKGROUND AND AIM: Anesthesiologist gain access to the airway passage orally with the help of laryngoscope. Dental trauma can occur during different steps in anesthesia. The aim of the study is to evaluate the risk factor for dental trauma perioperatively and to look for the preventive measures mostly employed by the anesthesiologist to prevent dental insult. MATERIALS AND METHODS: The present study involved 40 anesthetists working in private hospitals using simple random sampling. They were asked to answer a questionnaire designed to look for the risk factors that makes tooth most prone for injury and find out the measures that anesthesiologists follow to prevent such injuries to occur. Codes were placed for the obtained data and Medcalc statistical package was used for analysis. RESULTS: Injuries mostly occur during intubation with a laryngoscope in patients where there is limited visibility to the hypopharynx. Maxillary left central incisor was mostly affected. Some anesthetists used plastic blades or curved blades to prevent such injury. CONCLUSION: Patient with poor dentition and history of difficult intubation should be sent for pre-operative dental evaluation to prevent dental injuries.

Tryptophan environment and functional characterization of a kinetically stable serine protease containing a polyproline II fold.

The single tryptophan residue from Nocardiopsis sp. serine protease (NprotI) was studied for its microenvironment using steady state and time-resolved fluorescence. The emission maximum was observed at 353 nm with excitation at 295 nm indicating tryptophan to be solvent exposed. Upon denaturation with 6 M guanidinum thiocyanate (GuSCN) the emission maxima was shifted to 360 nm. Solute quenching studies were performed with neutral (acrylamide) and ionic (I(-) and Cs(+)) quenchers to probe the exposure and accessibility of tryptophan residue of the protein. Maximum quenching was observed with acrylamide. In the native state, quenching was not observed with Cs(+) indicating presence of only positively charged environment surrounding tryptophan. However; in denatured protein, quenching was observed with Cs(+), indicating charge reorientation after denaturation. No quenching was observed with Cs(+) even at pH 1.0 or 10.0; while at acidic pH, a higher rate of quenching was observed with KI. This indicated presence of more positive charge surrounding tryptophan at acidic pH. In time resolved fluorescence measurements, the fluorescence decay curves could be best fitted to monoexponential pattern with lifetimes of 5.13 ns for NprotI indicating one conformer of the trp. Chemical modification studies with phenyl glyoxal suggested presence of Arg near the active site of the enzyme. No inhibition was seen with soyabean trypsin and limabean inhibitors, while, CanPI uncompetitively inhibited NprotI. Various salts from Hofmeister series were shown to decrease the activity and PPII content of NprotI.

Re-directing an alkylating agent to mitochondria alters drug target and cell death mechanism.

We have successfully delivered a reactive alkylating agent, chlorambucil (Cbl), to the mitochondria of mammalian cells. Here, we characterize the mechanism of cell death for mitochondria-targeted chlorambucil (mt-Cbl) in vitro and assess its efficacy in a xenograft mouse model of leukemia. Using a ρ° cell model, we show that mt-Cbl toxicity is not dependent on mitochondrial DNA damage. We also illustrate that re-targeting Cbl to mitochondria results in a shift in the cell death mechanism from apoptosis to necrosis, and that this behavior is a general feature of mitochondria-targeted Cbl. Despite the change in cell death mechanisms, we show that mt-Cbl is still effective in vivo and has an improved pharmacokinetic profile compared to the parent drug. These findings illustrate that mitochondrial rerouting changes the site of action of Cbl and also alters the cell death mechanism drastically without compromising in vivo efficacy. Thus, mitochondrial delivery allows the exploitation of Cbl as a promiscuous mitochondrial protein inhibitor with promising therapeutic potential.

Polyproline fold-In imparting kinetic stability to an alkaline serine endopeptidase.

Polyproline II (PPII) fold, an unusual structural element was detected in the serine protease from Nocardiopsis sp. NCIM 5124 (NprotI) based on far UV circular dichroism spectrum, structural transitions of the enzyme in presence of GdnHCl and a distinct isodichroic point in chemical and thermal denaturation. The functional activity and conformational transitions of the enzyme were studied under various denaturing conditions. Enzymatic activity of NprotI was stable in the vicinity of GdnHCl upto 6.0M concentration, organic solvents viz. methanol, ethanol, propanol (all 90% v/v), acetonitrile (75% v/v) and proteases such as trypsin, chymotrypsin and proteinase K (NprotI:protease 10:1). NprotI seems to be a kinetically stable protease with a high energy barrier between folded and unfolded states. Also, an enhancement in the activity of the enzyme was observed in 1M GdnHCl upto 8h, in organic solvents (75% v/v) for 72h and in presence of proteolytic enzymes. The polyproline fold remained unaltered or became more prominent under the above mentioned conditions. However, it diminished gradually during thermal denaturation above 60°C. Thermal transition studies by differential scanning calorimetry (DSC) showed scan rate dependence as well as irreversibility of denaturation, the properties characteristic of kinetically stable proteins. This is the first report of PPII helix being the global conformation of a non structural protein, an alkaline serine protease, from a microbial source, imparting kinetic stability to the protein.

Tuning the activity of mitochondria-penetrating peptides for delivery or disruption.

Mitochondrially targeted agents have the capacity to be both vehicles for the delivery of bioactive agents and mitochondrial disrupters and show promise for the treatment of various diseases. Engineering these agents to specifically accumulate or disrupt the mitochondrion is challenging, as there is a fine line between characteristics of the molecules that accomplish each task. Here, we assess the physicochemical properties governing mitochondrial matrix accumulation or membrane disruption caused by mitochondria-penetrating peptides. Increases in peptide length and hydrophobicity were uncovered as the dominant factors in deriving membrane disruptive activity. Shorter, less hydrophobic peptides did not disrupt the mitochondrial membrane, but rather accumulated in the mitochondrial matrix without interfering with cellular activity. These shorter peptides, however, can trigger cytochrome c release through activation of the permeability transition pore complex (PTPC), but only at very high concentrations. This study illustrates that the activity of a mitochondria-localizing agent can be controlled through alterations in peptide hydrophobicity and dosing concentrations.

Rerouting chlorambucil to mitochondria combats drug deactivation and resistance in cancer cells.

The difficulty of accessing the mitochondrial matrix has limited the targeting of therapeutics to this organelle. Here, we report, to our knowledge, the first successful delivery of an active DNA alkylating agent--chlorambucil--to mitochondria, and describe unexpected features that result from rerouting this drug within the cell. Mitochondrial targeting of this agent dramatically potentiates its activity, and promotes apoptotic cell death in a variety of cancer cell lines and patient samples. This retention of activity is observed even in cells with resistance to chlorambucil or disabled apoptotic triggering.