Labeling of epirubicin with technetium-99m: Optimization, biodistribution and scintigraphic imaging in tumor bearing mice.

Epirubicin is an antineoplastic agent of anthracycline antibiotic, used for treating a variety of tumor types such as lymphoma, cancer of the breast, lung, ovary and stomach. The objective of this work was to demonstrate direct radiolabeling of epirubicin with 99mTc, quality control, biological characterization and scientigraphic evaluation in tumor bearing mice. The 99mTc-epirubicin labeling was optimized by varying the amounts of ligand 100-350µg, stannous chloride dihydride 20-50µg and pH range 2-10 by using NaOH or HCl. The radiochemical purity of 99mTc-epirubicin was evaluated by chromatographic techniques (Whatman No. 3 paper and ITLC-SG). HPLC analyses were performed to check purity of epirubicin and radiochemical purity of labeled 99mTc- epirubicin. Biodistribution and scintigraphic imaging of 99mTc-epirubicin was performed in normal and tumor bearing mice at various time intervals. The optimum conditions ensuring 99mTc-epirubicin labeling yield as high as 99% by adding 35µg SnCl2.2H2O, 200µg of ligand at pH 6 for 30 min at room temperature (25°C±2°C). HPLC of 99mTc-epirubicin shows about 99% binding of the compound with technetium-99m. Electrophoresis study indicated the neutral nature of 99mTc-epirubicin. Biodistribution data and scintigraphic results showed that 99mTc-epirubicin accumulated in the liver as well as in tumor with significant uptake and excellent retention. 99mTc-epirubicin shows good stability in human serum. In vitro and in vivo studies revealed the significantly uptake of 99mTc-epirubicin in the tumor, and also indicating the efficiency of 99mTc-epirubicin as a tumor diagnostic agent.

Fungal Biomass Protein Production from Trichoderma harzianum Using Rice Polishing.

Industrially important enzymes and microbial biomass proteins have been produced from fungi for more than 50 years. High levels of crude protein as much as 45% are present in fungal biomass with balanced essential amino acids. The aim of this study was to access the potential of Trichoderma harzianum to produce fungal biomass protein from rice polishings. Maximum biomass yield was obtained at 5% (w/v) rice polishings after 72 h of incubation at 28°C at pH 4. Carbon and nitrogen ratio of 20 : 1 gave significantly higher production of fungal biomass protein. The FBP in the 75 L fermenter contained 49.50% crude protein, 32.00% true protein, 19.45% crude fiber, 9.62% ash, 11.5% cellulose content, and 0.325% RNA content. The profile of amino acids of final FBP exhibited that all essential amino acids were present in great quantities. The FBP produced by this fungus has been shown to be of good nutritional value for supplementation to poultry. The results presented in this study have practical implications in that the fungus T. harzianum could be used successfully to produce fungal biomass protein using rice polishings.

Molecular cloning and comparative sequence analysis of fungal ß-Xylosidases.

Commercial scale degradation of hemicelluloses into easily accessible sugar residues is practically crucial in industrial as well as biochemical processes. Xylanolytic enzymes have a great number of possible applications in many biotechnological processes and therefore, these enzymes are continuously attracting the attention of scientists. Due to this fact, different ß-Xylosidases have been isolated, purified and characterized from several bacteria and fungi. Microorganisms in this respect have gained much momentum for production of these significant biocatalysts with remarkable features. It is difficult to propagate microorganisms for efficient and cost-competitive production of ß-Xylosidase from hemicelluloses due to expensive conditions of fermentation. The screening of new organisms with an enhanced production of ß-Xylosidases has been made possible with the help of recombinant DNA technology. ß-Xylosidase genes haven been cloned and expressed on large scale in both homologous and heterologous hosts with the advent of genetic engineering. Therefore, we have reviewed the literature regarding cloning of ß-Xylosidase genes into various hosts for their heterologous production along with sequence similarities among different ß-Xylosidases. The study provides insight into the current status of cloning, expression and sequence analysis of ß-Xylosidases for industrial applications.

Relationship of oxidative stress with elevated level of DNA damage and homocysteine in cardiovascular disease patients.

Amounts of DNA damage and homocysteine (Hcy) in heart patients blood may have strong function in the causation of cardiovascular disease (CVD). The main objective of this work was to know experimentally the role of total oxidants (produced by Reactive Oxygen species (ROS), clinical biochemical indices, their oxidized products and total antioxidant status (TAS) among such patients to find the association of homocysteine, total oxidation status (TOS) and oxidative DNA damage with other clinical parameters in sixty positive CVD patients compared with those of 60 normal subjects. As compared to healthy individuals, CVD patients had significantly higher concentrations of homocysteine (p<0.0001), total oxidants stress (TOS) (p<0.0001), serum total lipids (p<0.04), malondialdehyde (MDA) (p<0.001), high density lipoprotein-cholesterol (HDL-C) (p<0.0001), and low density lipoprotein cholesterol (LDL-C) (p<0.01), than those of healthy individuals. Plasma Hcy content, TOS and amount of DNA were positively and significantly associated with cholesterol, triglycerides, systolic blood pressure, urea, and albumin (p values<0.01). TOS, Hcy and oxidative DNA damage were negatively correlated with HDL-c, TAS and proteins. It is suggested that these parameters have pivotal role in diagnostic process of determining severity in CAD patients. Oxidized products of macromolecules in blood of CVD patients impart major functions in causing CVD disease.

Determination of substrate specificities against ß-glucosidase A (BglA) from Thermotoga maritime: a molecular docking approach.

Thermostable enzymes derived from Thermotoga maritima have attracted worldwide interest for their potential industrial applications. Structural analysis and docking studies were preformed on T. maritima ß-glucosidase enzyme with cellobiose and pNP-linked substrates. The 3D structure of the thermostable ß-glucosidase was downloaded from the Protein Data Bank database. Substrates were downloaded from the PubCehm database and were minimized using MOE software. Docking of BglA and substrates was carried out using MOE software. After analyzing docked enzyme/substrate complexes, it was found that Glu residues were mainly involved in the reaction, and other important residues such as Asn, Ser, Tyr, Trp, and His were involved in hydrogen bonding with pNP-linked substrates. By determining the substrate recognition pattern, a more suitable ß-glucosidase enzyme could be developed, enhancing its industrial potential.

Preparation, biodistribution, and scintigraphic evaluation of (99m)Tc-clindamycin: an infection imaging agent.

Bacterial infection is found to be the cause of death throughout the world. Nuclear medicine imaging with the help of radiopharmaceuticals has great potential for treating infections. In the present work, clindamycin, a lincosamide antibiotic, was labeled with technetium-99 m (~380 MBq). Clindamycin has been proven to be efficient for treating serious infections caused by bacteria such as Staphylococcus aureus. Quality control, characterization, biodistribution, and scintigraphy of radiolabeled clindamycin were done, and labeling efficiency was determined by ascending paper chromatography. More than 95 % labeling efficiency with technetium-99 m ((99m)Tc) was achieved at pH 6-7 while using 2.5-3 µg SnCl2 · H2O as a reducing agent and 100 µg of ligand at room temperature. The characterization of the compound was performed by using electrophoresis, HPLC and shake flask assay. Electrophoresis indicates the neutral behavior of (99m)Tc-clindamycin. HPLC analysis confirms the single specie of the labeled compound, while shake flask assay confirms high lipophilicity. The biodistribution studies of (99m)Tc-clindamycin were performed Sprague Dawley rats bearing bacterial infection. Scintigraphy and biodistribution studies showed a high uptake of (99m)Tc-clindamycin in the liver, heart, lung, and stomach as well as at S. aureus-infected sites in rabbits.

Solid State Fermentation of a Raw Starch Digesting Alkaline Alpha-Amylase from Bacillus licheniformis RT7PE1 and Its Characteristics.

The thermodynamic and kinetic properties of solids state raw starch digesting alpha amylase from newly isolated Bacillus licheniformis RT7PE1 strain were studied. The kinetic values Q p , Y p/s , Y p/X , and q p were proved to be best with 15% wheat bran. The molecular weight of purified enzyme was 112 kDa. The apparent K m and V max values for starch were 3.4 mg mL(-1) and 19.5 IU mg(-1) protein, respectively. The optimum temperature and pH for α -amylase were 55°C, 9.8. The half-life of enzyme at 95°C was 17h. The activation and denaturation activation energies were 45.2 and 41.2 kJ mol(-1), respectively. Both enthalpies (ΔH (∗)) and entropies of activation (ΔS (∗)) for denaturation of α -amylase were lower than those reported for other thermostable α -amylases.

Kinetics and thermodynamics of ethanol production by Saccharomyces cerevisiae MLD10 using molasses.

In this study, we have used ultraviolet (UV) and γ-ray induction to get a catabolite repression resistant and thermotolerant mutant with enhanced ethanol production along with optimization of sugar concentration and temperature of fermentation. Classical mutagenesis in two consecutive cycles of UV- and γ-ray-induced mutations evolved one best catabolite-resistant and thermotolerant mutant Saccharomyces cerevisiae MLD10 which showed improved ethanol yield (0.48 ± 0.02 g g(-1)), theoretical yield (93 ± 3%), and extracellular invertase productivity (1,430 ± 50 IU l(-1) h(-1)), respectively, when fermenting 180 g sugars l(-1) in molasses medium at 43 °C in 300 m(3) working volume fermenter. Ethanol production was highly dependent on invertase production. Enthalpy (ΔH*) (32.27 kJ M(-1)) and entropy (ΔS*) (-202.88 J M(-1) K(-1)) values at 43 °C by the mutant MLD10 were significantly lower than those of ß-glucosidase production by a thermophilic mutant derivative of Thermomyces lanuginosus. These results confirmed the enhanced production of ethanol and invertase by this mutant derivative. These studies proved that mutant was significantly improved for ethanol production and was thermostable in nature. Lower fermentation time for ethanol production and maintenance of ethanol production rates (3.1 g l(-1) h(-1)) at higher temperature (43 °C) by this mutant could decrease the overall cost of fermentation process and increase the quality of ethanol production.

Kinetic and thermodynamic characterization of lysine production process in Brevibacterium lactofermentum.

Detailed kinetic and thermodynamic parameters for lysine production from Brevibacterium lactofermentum are investigated for the first time in this study. Production of the essential amino acid, L-lysine, by B. lactofermentum was assessed in a flask and a continuously stirred tank fermentor (22 L). Maximum lysine production was achieved after 40 h of growth and at 35 °C. The effect of different nitrogen sources such as NH(4)NO(3), (NH(4))(2)SO(4), (NH(4))(2)HPO(4), corn steep liquor, NaNO(3), and urea showed that corn steep liquor gave a better lysine yield. Lysine production was increased when dissolved oxygen was maintained at 50 % saturation. The use of dissolved oxygen was critical for high productivity. This indicates that dissolved oxygen greatly affects L-lysine productivity. Kinetic and thermodynamic parameters during lysine production from molasses and glucose mixture showed that B. lactofermentum efficiently converted the substrate mixture into cell mass and lysine. Kinetic and thermodynamic parameters were significantly higher compared with other microorganisms which may be due to the high metabolic activity of B. lactofermentum. This study will have a significant impact on future strategies for lysine production at industrial scale.

Characterization of a thermostable and alkaline xylanase from Bacillus sp. and its bleaching impact on wheat straw pulp.

Delignification efficacy of xylanases to facilitate the consequent chemical bleaching of Kraft pulps has been studied widely. In this work, an alkaline and thermally stable cellulase-less xylanase, derived from a xylanolytic Bacillus subtilis, has been purified by a combination of gel filtration and Q-Sepharose chromatography to its homogeneity. Molecular weight of the purified xylanase was 61 kDa by SDS-PAGE. The purified enzyme revealed an optimum assay temperature and pH of 60°C and 8.0, respectively. Xylanase was active in the pH range of 6.0-9.0 and stable up to 70°C. Divalent ions like Ca(2+), Mg(2+) and Zn(2+) enhanced xylanase activity, whereas Hg(2+), Fe(2+), and Cu(2+) were inhibitory to xylanase at 2 mM concentration. It showed K ( m ) and V ( max ) values of 9.5 mg/ml and 53.6 µmol/ml/min, respectively, using birchwood xylan as a substrate. Xylanase exhibited higher values of turn over number (K (cat)) and catalytic efficiency (K (cat)/K (m)) with birchwood xylan than oat spelt xylan. Bleach-boosting enzyme activity at 30 U/g dry pulp displayed the optimum bio-delignification of Kraft pulp resulting in 26.5% reduction in kappa number and 18.5% ISO induction in brightness at 55°C after 3 h treatment. The same treatment improved the pulp properties including tensile strength and burst index, demonstrating its potential application in pre-bleaching of Kraft pulp.

Polyhexamethylene biguanide functionalized cationic silver nanoparticles for enhanced antimicrobial activity.

Polyhexamethylene biguanide (PHMB), a broad spectrum disinfectant against many pathogens, was used as a stabilizing ligand for the synthesis of fairly uniform silver nanoparticles. The particles formed were characterized using UV-visible spectroscopy, FTIR, dynamic light scattering, electrophoretic mobility, and TEM to measure their morphology and surface chemistry. PHMB-functionalized silver nanoparticles were then evaluated for their antimicrobial activity against a gram-negative bacterial strain, Escherichia coli. These silver nanoparticles were found to have about 100 times higher bacteriostatic and bactericidal activities, compared to the previous reports, due to the combined antibacterial effect of silver nanoparticles and PHMB. In addition to other applications, PHMB-functionalized silver nanoparticles would be extremely useful in textile industry due to the strong interaction of PHMB with cellulose fabrics.

Heterologous expression of a gene for thermostable xylanase from Chaetomium thermophilum in Pichia pastoris GS115.

We studied heterologous expression of xylanase 11A gene of Chaetomium thermophilum in Pichia pastoris and characterized the thermostable nature of the purified gene product. For this purpose, the xylanase 11A gene of C. thermophilum was cloned in P. pastoris GS115 under the control of AOX1 promoter. The maximum extracellular activity of recombinant xylanase (xyn698: gene with intron) was 15.6 U ml(-1) while that of recombinant without intron (xyn669) was 1.26 U ml(-1) after 96 h growth. The gene product was purified apparently to homogeneity level. The optimum temperature of pure recombinant xylanase activity was 70°C and the enzyme retained its 40.57% activity after incubation at 80°C for 10 min. It exhibited quite lower demand of activation energy, enthalpy, Gibbs free energy, entropy, and xylan binding energy during substrate hydrolysis than that required by that of the donor, thus indicating its thermostable nature. pH-dependent catalysis showed that it was quite stable in a pH range of 5.5-8.5. This revealed that gene was successfully processed in P. pastoris and remained heat stable and may qualify for its potential use in paper and pulp and animal feed applications.

Oxidative stress elevated DNA damage and homocysteine level in normal pregnant women in a segment of Pakistani population.

Maternal oxidative stress during pregnancy may impair fetal growth and help in the development of diseases in adulthood. The aim of current study was to assess total oxidation status (TOS), related parameters and their relationship to DNA damage (%) and homocysteine level in normal pregnant women in low-income participants. In a cross-sectional study healthy women were grouped as normal, while age matched nulliparous and singleton pregnancies were included for first, second and third trimester groups. TOS (P<0.01), melanodialdehyde (MDA) (P<0.001), aspartate aminotransferase (AST) (P<0.01), triiodothyronine (T3) (P<0.01), thyroxine (T4) (P<0.01), and homocysteine (P<0.001), in pregnant women were significantly higher as compared to normal healthy women. While serum total proteins (P<0.01), albumin (P<0.01) and total antioxidant status (TAS) (P<0.001) decreased significantly as compared to normal healthy women. Women in third trimester showed a significantly high level of body temperature (P<0.01), triglyceride (P<0.01), LDL-cholesterol (P<0.05), AST (P<0.01), T3 (P<0.01), homocysteine (P<0.001), TOS (P<0.01) and MDA (P<0.001) but a lower concentration of serum proteins, albumin and TAS at the end of the pregnancy. Pearson correlation indicated a positive relationship of homocysteine with triglycerides (P<0.027), TOS (P<0.01), MDA (P<0.035) and had a negative relationship with total protein (P<0.026). DNA damage was strongly related with T3 (P<0.008), TOS (P<0.02), MDA (P<0.037) and MBI (P<0.048) profiles of pregnant women. These changes were considered normal for pregnant women having optimum blood pressure and normal child birth. Hormonal influences and hemodilution may contribute towards the observed changes in this study.

Optimized expression of a thermostable xylanase 11 A gene from Chaetomium thermophilum NIBGE 1 in Escherichia coli.

The xylanase (Xyn11A) gene (883 bp) was amplified using C. thermophilum DNA as template and cloned into pET-32a (+) and expressed in E. coli BL21 under T(7) promoter. The recombinant xylanase on SDS-PAGE had a molecular mass of 30 kDa. Productivity profiles of xylanase in E. coli recombinant are more than 4-fold of that produced from T. reesei RUTC-30, 5-fold of that produced by the donor and significantly higher than the values reported on other E. coli, and Saccharomyces cerevisiae recombinants. Temperature stability, pH stability, and other kinetic parameters confirmed that the gene product was thermo-stable in alkaline buffer favoring its suitability to bio-bleaching of kraft pulp.

Kinetics of high-level of ß-glucosidase production by a 2-deoxyglucose-resistant mutant of Humicola lanuginosa in submerged fermentation / Cinética de produção de ß-glucosidase por um mutante de Hemicola lanuginosa resistente a 2-deoxiglucose em fermentação submersa

A 2-deoxyglucose-resistant mutant (M7) of Humicola lanuginosa was obtained by exposing conidia to γ-rays and permitting expression in broth containing 0.6 percent 2-deoxyglucose (DG) and cellobiose (1 percent) before plating on DG esculin-ferric ammonium citrate agar medium from which colonies showing faster and bigger blackening zones were selected. Kinetic parameters for enhanced ß-glucosidase (BGL) synthesis by M7 were achieved when corncobs acted as the carbon source. The combination between corncobs and corn steep liquor was the best to support higher values of all product formation kinetic parameters. Effect of temperature on the kinetic and thermodynamic attributes of BGL production equilibrium in the wild organismand M7was studied using batch process at eight different temperatures in shake-flask studies. The best performance was found at 45ºC and 20 g L-1 corncobs in 64 h. Both growth and product formation (17.93 U mL-1) were remarkably high at 45ºC and both were coupled under optimum working conditions. Product yield of BGL from the mutant M7 (1556.5 U g-1 dry corncobs) was significantly higher than the values reported on all fungal and bacterial systems. Mutation had thermo-stabilization influence on the organism and mutant required lower activation energy for growth and lower magnitudes of enthalpy and entropy for product formation than those demanded by the wild organism, other mesophilic and thermo-tolerant organisms. In the inactivation phase, the organisms needed lower values of activation energy, enthalpy and entropy for product formation equilibrium, confirming thermophilic nature of metabolic network possessed by the mutant organism.

Um mutante de Hemicola lanuginosa resistente a 2-deoxiglucose(M7) foi obtido através de exposição de conídios a raios γ, permitindo a expressão em caldo contendo 0,6 por cento de 2-deoxiglucose (DG) e celobiose (1 por cento) antes da semeadura em ágar DG esculina citrato de ferro amoniacal, da qual foram selecionadas as colônias com halo negro. Os parâmetros cinéticos para produção aumentada de ß-glucosidase (BGL) foram obtidos empregando-se sabugo de milho como fonte de carbono. A combinação de espiga de milho com água de maceração de milho foi a que forneceu os valores mais altos nos parâmetros cinéticos de formação de todos os produtos. O efeito da temperatura na cinética e atributos termodinâmicos da produção de BGL pelas cepas selvagem e M7 foi avaliado empregando-se processo de batelada em oito temperaturas diferentes in frascos em agitação. O melhor desempenho foi observado a 45ºC e 20g.l-1 de espiga de milho em 64h. Tanto a multiplicação quanto a formação do produto foram muito altas a 45ºC e ambas estavam ligadas em condições ótimas de trabalho. O rendimento de BGL produzido pelo mutante M7 (1556 U.g-1 de espiga seca) foi significativamente superior aos valores reportados para todos os sistemas fúngicos e bacterianos. A mutação influenciou a termoestabilização no microrganismo, sendo que o mutante necessitou de energia de ativação mais baixa para multiplicação e valores mais baixos de entalpia e entropia para a formação do produto quando comparado à cepa selvagem e a outros microrganismos mesofilicos e termotolerantes. Na fase de inativação, os microrganismos necessitaram valores mais baixos de energia de ativação, entalpia e entropia para o equilíbrio da formação de produto, confirmando a natureza termofílica da máquina metabólica do mutante.

Production, purification and characterization of beta-1,4-endoglucanase from a novel bacterial strain CTP-09 of a Bacillus sp.

Bacillus strain CTP-09 yielded maximum productivity (1120 IU/L.h) of extracellular endoglucanase (CMCase) on 0.5% cellobiose after 10 h fermentation at 55 degrees C. The purified enzyme is mono-meric in nature and exhibits stability up to 80 degrees C and over a pH range (6.0-9.0). Activation energy, enthalpy and entropy of catalysis, and inactivation indicated that this CMCase is highly thermos-table. Purified enzyme possessed high power of defibrillation of textile and was minutely inhibited by anionic detergent and oxidizing agent comparable with inhibition by commercial enzyme. This polypeptide could be exploited for mass production and application in local industries.

Kinetics of high-Level of ß-glucosidase production by a 2-deoxyglucose-resistant mutant of Humicola lanuginosa in submerged fermentation.

A 2-deoxyglucose-resistant mutant (M7) of Humicola lanuginosa was obtained by exposing conidia to γ-rays and permitting expression in broth containing 0.6% 2-deoxyglucose (DG) and cellobiose (1%) before plating on DG esculin-ferric ammonium citrate agar medium from which colonies showing faster and bigger blackening zones were selected. Kinetic parameters for enhanced ß-glucosidase (BGL) synthesis by M7 were achieved when corncobs acted as the carbon source. The combination between corncobs and corn steep liquor was the best to support higher values of all product formation kinetic parameters. Effect of temperature on the kinetic and thermodynamic attributes of BGL production equilibrium in the wild organism and M7 was studied using batch process at eight different temperatures in shake-flask studies. The best performance was found at 45°C and 20 g L(-1) corncobs in 64 h. Both growth and product formation (17.93 U mL(-1)) were remarkably high at 45°C and both were coupled under optimum working conditions. Product yield of BGL from the mutant M7 (1556.5 U g(-1) dry corncobs) was significantly higher than the values reported on all fungal and bacterial systems. Mutation had thermo-stabilization influence on the organism and mutant required lower activation energy for growth and lower magnitudes of enthalpy and entropy for product formation than those demanded by the wild organism, other mesophilic and thermo-tolerant organisms. In the inactivation phase, the organisms needed lower values of activation energy, enthalpy and entropy for product formation equilibrium, confirming thermophilic nature of metabolic network possessed by the mutant organism.

A surface immobilization method of endoglucanase from Cellulomonas biazotea mutant improved catalytic properties of biocatalyst during processing.

Purified endoglucanase from C. biazotea mutant 51SM(r) was successfully immobilized on Eudragit L-100, with 75 % yield of immobilization. This method improved the kinetic and thermodynamic properties of the enzyme. Immobilization significantly decreased entropy and enthalpy of inactivation of biocatalyst and made it functionally and thermodynamically more stable and reusable compared to free one.

Kinetic and thermodynamic properties of an immobilized glucoamylase from a mesophilic fungus, Arachniotus citrinus.

Purified glucoamylase from Arachniotus citrinus was immobilized on polyacrylamide gel with 70% yield of immobilization. The immobilization improved the pH optima, temperature optima, values of K(m), V(max), and activation energy. Irreversible thermal denaturation studies of soluble and immobilized glucoamylase indicated that immobilization decreased the entropy and enthalpy of deactivation by magnitudes and made the immobilized glucoamylase thermodynamically more stable.

Purification, and properties of a bovine uricase.

Uricase from bovine kidney, purified to homogeneity level, had a molecular weight of 70 kDa. The apparent K(m) and V(max) values for uric acid hydrolysis were 0.125 mM and 102 IU mg(-1) protein respectively. The activation energy requirement for uric acid hydrolysis by uricase and inactivation of enzyme were 11.6 and 14.5 kJ/M respectively. Both enthalpy (Delta H*) and entropy of activation (Delta S*) for uricase activity were lower than those reported for some thermostable enzymes.