Effect of hydrophobic property on antibacterial activities of green tea polysaccharide conjugates against Escherichia coli.

We previously found that green tea polysaccharide conjugates (gTPCs) have antibacterial activity against Escherichia coli. In this study, the effect of hydrophobic property on the antibacterial activities of gTPCs was evaluated to elucidate their property-activity relationship. Three gTPCs (gTPCs-5 h, gTPCs-12 h and gTPCs-24 h) were extracted from green tea with the ethanol precipitation time of 5 h, 12 h and 24 h, respectively. These three gTPCs did not differ significantly in terms of molecular weight distribution, amino acids composition and zeta potentials. Fourier transform infrared spectroscopy results revealed that gTPCs-5 h and gTPCs-12 h processed more hydrogen bonds than gTPCs-24 h. The surface hydrophobicity and contact angle of gTPCs-5 h were larger than that of gTPCs-12 h and gTPCs-24 h. The antibacterial activity of gTPCs against E. coli decreased in the order of gTPCs-5 h > gTPCs-12 h > gTPCs-24 h. There wasn't significant difference among the zeta potentials of E. coli treated by gTPCs-5 h, gTPCs-12 h and gTPCs-24 h, but the bacterial contact angles of E. coli treated by gTPCs-5 h were higher compared with those of the other two gTPCs. Furthermore, gTPCs-5 h exhibited higher activity to decrease bacterial membrane proteins, and increase bacterial membrane permeability than the other two gTPCs. In conclusion, gTPCs with higher hydrophobicity property exhibited stronger antibacterial activity against E. coli.

Heteroleptic/Heterometallic Sierpinski Triangle with Room Temperature Fluorescence Emission and Photocatalytic Amine Oxidation Activity.

As a result of their optical and redox properties, bipyridyl (bpy) and terpyridyl (tpy) ruthenium complexes play vital roles in numerous domains. Herein, the design and synthesis of two bipyridyl and terpyridyl ruthenium(II) building units L1 and L2 are explained. A [Ru(bpy)3]2+ functionalized triangle S1 and a Sierpinski triangle S2 were synthesized in almost quantitative yields by the self-assembly of L1 with Zn2+ ions and by the heteroleptic self-assembly of L1 and L2 with Zn2+ ions, respectively. The Sierpinski triangle S2 contains the coordination metals [Ru(bpy)3]2+, [Ru(tpy)2]2+, and [Zn(tpy)2]2+. According to research on the catalytic activity of amine oxidation on supramolecules S1 and S2, the benzylamine substrates were nearly entirely transformed to N-benzylidenebenzylamine derivatives after 1 h under a Xe lamp. Furthermore, the observed ruthenium-containing terpyridyl supramolecule S2 maintains high luminous performance at ambient temperature. This discovery opens up new possibilities for the rational molecular design of terpyridyl ruthenium fluorescent materials and catalytic functional materials.

The Marriage of Sierpinski Triangles and Platonic Polyhedra.

Fractal structures with self-similarity are of fundamental importance in the fields of aesthetic, chemistry and mathematics. Here, by taking advantage of constructs the rational geometry-directed precursor design, we report the construction of two fascinating Platonic solids, the Sierpinski tetrahedron ST-T and the Sierpinski octahedron ST-O, in which each possesses a fractal Sierpinski triangle on their independent faces. These two discrete complexes are formed in near-quantitative yield from the multi-component self-assembly of truncated Sierpinski triangular kernel L1 with tribenzotriquinacene-based hexatopic and anthracene-based tetratopic terpyridine ligands (L3 and L4 ) in the presence of metal ions, respectively. The enhanced stabilities of the 3D discrete structures were investigated by gradient tandem mass spectrometry (gMS2 ). This work provides new constructs for the imitation of complex virus assemblies and for the molecular encapsulation of giant guest molecules.

The Development of Hsp90ß-Selective Inhibitors to Overcome Detriments Associated with pan-Hsp90 Inhibition.

The 90 kD heat shock proteins (Hsp90) are molecular chaperones that are responsible for the folding of select proteins, many of which are directly associated with cancer progression. Consequently, inhibition of the Hsp90 protein folding machinery results in a combinatorial attack on numerous oncogenic pathways. Seventeen small-molecule inhibitors of Hsp90 have entered clinical trials for the treatment of cancer, all of which bind the Hsp90 N-terminus and exhibit pan-inhibitory activity against all four Hsp90 isoforms, which may lead to adverse effects. The development of Hsp90 isoform-selective inhibitors represents an alternative approach toward the treatment of cancer and may limit some of these detriments. Described herein, is a structure-based approach to develop isoform-selective inhibitors of Hsp90ß, which induces the degradation of select Hsp90 clients without concomitant induction of Hsp90 levels. Together, these initial studies support the development of Hsp90ß-selective inhibitors as a method for overcoming the detriments associated with pan-inhibition.

Glycemic impact of a diet and lifestyle intervention on diabetics and prediabetics during treatment for non-muscle invasive bladder cancer.

Introduction: Patients with Type II Diabetes Mellitus (DM2) have increased risk of recurrence and progression of non-muscle invasive bladder cancer (NMIBC). Glucose control through lifestyle intervention is an uninvestigated, attractive strategy to decrease risk of cancer recurrence. We test the feasibility of a diet and exercise program and its glycemic impact in patients with DM2 and NMIBC.Materials/methods: Five participants with NMIBC and pre-diabetes or DM2 were recruited for a pilot, prospective clinical trial. Each participant received dietary counseling for 16 sessions during clinical visits. The intervention included a carbohydrate-restricted (CR) diet (<130 grams per day), 30 min, walking 5×/wk, and 5000 steps daily. Diet compliance was measured with 24-hour diet recall. Exercise was monitored with accelerometer and self-report.Results: Five participants enrolled and two participants completed the 12-month intervention. Adherence was 60% to CR diet and 84% to exercise goals. Participants reduced carbohydrate consumption by 44%. Participants showed reductions in fasting blood glucose, HbA1c, glucosuria, fasting blood insulin, and body weight, and increased euglycemia on continuous glucose monitoring.Conclusions: Adherence to a CR diet and exercise goals is feasible in patients with NMIBC and DM2 and also leads improved glucose control. A phase-II trial on bladder cancer-specific outcomes is warranted.

Tumor M2-PK: A novel urine marker of bladder cancer.

PURPOSE: Bladder cancer is a "Warburg-like" tumor characterized by a reliance on aerobic glycolysis and expression of pyruvate kinase M2 (PKM2). PKM2 oscillates between an active tetramer and an inactive dimer. We aim to further characterize PKM2, in particular PKM2 dimer, as a urinary biomarker of bladder cancer and a potential target for treatment. METHODS: HTB-9, HTB-5, and UM-UC3 bladder cancer cells were assessed for proliferation under differential glucose levels using the hexosaminidase assay. Western blot and Blue-native analysis was performed for protein expression of PKM2. Shikonin, an herb that is known to bind and inhibit PKM2, was utilized to determine if PKM2 has a role in glucose usage and cellular proliferation in bladder cancer cells by caspase activity assay. Institutional review board approval was obtained to collect healthy control and bladder cancer patient urine samples. The ScheBo M2-PK EDTA Plasma Test was performed on urine samples to assess urine Tumor M2-PK values. RESULTS: The three bladder cancer cell lines tested all demonstrate statistically significant increases in proliferation when exposed to higher level of glucose (200mg/dL). Similarly, low doses of glucose (25mg/dL) result in reduced proliferation. Increased cell growth in higher glucose concentration correlated with up-regulation of PKM2 protein expression. Shikonin, a PKM2 inhibitor, reduced cell proliferation and switched PKM2 isoforms from the dimer to tetramer. Lastly, dimer PKM2 (Tumor-M2PK) levels were assessed in the urine samples from bladder cancer (Bca) patients and healthy controls. Tumor M2-PK significantly correlated with the presence of BCa in our subjects. CONCLUSIONS: Our studies demonstrate the potential of PKM2, specifically the dimer (Tumor-M2PK) as a target of drug therapy and as a urinary marker for bladder cancer.

Structure-guided design of an Hsp90ß N-terminal isoform-selective inhibitor.

The 90 kDa heat shock protein (Hsp90) is a molecular chaperone responsible for folding proteins that are directly associated with cancer progression. Consequently, inhibition of the Hsp90 protein folding machinery results in a combinatorial attack on numerous oncogenic pathways. Seventeen small-molecule inhibitors of Hsp90 have entered clinical trials, all of which bind the Hsp90 N-terminus and exhibit pan-inhibitory activity against all four Hsp90 isoforms. pan-Inhibition of Hsp90 appears to be detrimental as toxicities have been reported alongside induction of the pro-survival heat shock response. The development of Hsp90 isoform-selective inhibitors represents an alternative approach towards the treatment of cancer that may limit some of the detriments. Described herein is a structure-based approach to design isoform-selective inhibitors of Hsp90ß, which induces the degradation of select Hsp90 clients without concomitant induction of Hsp90 levels. Together, these initial studies support the development of Hsp90ß-selective inhibitors as a method to overcome the detriments associated with pan-inhibition.

Modified biphenyl Hsp90 C-terminal inhibitors for the treatment of cancer.

Heat Shock Protein 90 (Hsp90) is a molecular chaperone under clinical investigation for the treatment of neurodegenerative diseases and cancer. Neuroprotective Hsp90 C-terminal inhibitors (novologues) contain a biaryl ring system, and include KU-596, which was modified and investigated for potential anti-cancer activity. Incorporation of a benzamide group onto the biaryl novologues in lieu of the acetamide yielded compounds that manifest anti-cancer activity. Further exploration of the central phenyl ring led to compounds with enhanced anti-proliferative activity. The design, synthesis, and evaluation of these new analogs against breast and prostate cancer cell lines is reported herein, where it was found that 8b and 10 manifest potent anti-proliferative activity and a robust degradation of Hsp90 client-dependent proteins.

Synthesis and Biological Evaluation of Novobiocin Core Analogues as Hsp90 Inhibitors.

Development of heat shock protein 90 (Hsp90) C-terminal inhibitors has emerged as an exciting strategy for the treatment of cancer. Previous efforts have focused on modifications to the natural products novobiocin and coumermycin. Moreover, variations in both the sugar and amide moieties have been extensively studied, whereas replacements for the coumarin core have received less attention. Herein, 24 cores were synthesized with varying distances and angles between the sugar and amide moieties. Compounds that exhibited good anti-proliferative activity against multiple cancer cell lines and Hsp90 inhibitory activity, were those that placed the sugar and amide moieties between 7.7 and 12.1 Šapart along with angles of 180°.

KU675, a Concomitant Heat-Shock Protein Inhibitor of Hsp90 and Hsc70 that Manifests Isoform Selectivity for Hsp90α in Prostate Cancer Cells.

The 90-kDa heat-shock protein (Hsp90) assists in the proper folding of numerous mutated or overexpressed signal transduction proteins that are involved in cancer. Inhibiting Hsp90 consequently is an attractive strategy for cancer therapy as the concomitant degradation of multiple oncoproteins may lead to effective antineoplastic agents. Here we report a novel C-terminal Hsp90 inhibitor, designated KU675, that exhibits potent antiproliferative and cytotoxic activity along with client protein degradation without induction of the heat-shock response in both androgen-dependent and -independent prostate cancer cell lines. In addition, KU675 demonstrates direct inhibition of Hsp90 complexes as measured by the inhibition of luciferase refolding in prostate cancer cells. In direct binding studies, the internal fluorescence signal of KU675 was used to determine the binding affinity of KU675 to recombinant Hsp90α, Hsp90ß, and Hsc70 proteins. The binding affinity (Kd) for Hsp90α was determined to be 191 µM, whereas the Kd for Hsp90ß was 726 µM, demonstrating a preference for Hsp90α. Western blot experiments with four different prostate cancer cell lines treated with KU675 supported this selectivity by inducing the degradation of Hsp90α -: dependent client proteins. KU675 also displayed binding to Hsc70 with a Kd value at 76.3 µM, which was supported in cellular by lower levels of Hsc70-specific client proteins on Western blot analyses. Overall, these findings suggest that KU675 is an Hsp90 C-terminal inhibitor, as well as a dual inhibitor of Hsc70, and may have potential use for the treatment of cancer.

Synthesis and biological evaluation of coumarin replacements of novobiocin as Hsp90 inhibitors.

Since Hsp90 modulates all six hallmarks of cancer simultaneously, it has become an attractive target for the development of cancer chemotherapeutics. In an effort to develop more efficacious compounds for Hsp90 inhibition, novobiocin analogues were prepared by replacing the central coumarin core with naphthalene, quinolinone, and quinoline surrogates. These modifications allowed for modification of the 2-position, which was previously unexplored. Biological evaluation of these compounds suggests a hydrophobic pocket about the 2-position of novobiocin. Anti-proliferative activities of these analogues against multiple cancer cell lines identified 2-alkoxyquinoline derivatives to exhibit improved activity.

PAHs in organic film on glass window surfaces from central Shanghai, China: distribution, sources and risk assessment.

Polycyclic aromatic hydrocarbons (PAHs) concentrations were analysed in the organic film on the glass surfaces of different functional areas in central Shanghai. Concentration levels of total PAHs in the organic film ranged from 1,348.5 to 4,007.9 ng m(-2). The concentration of PAHs was lowest in parks and green spaces (1,348.5 ng m(-2)) and highest in traffic zones (4,007.9 ng m(-2)). A concentration gradient of total PAHs was observed as follows: traffic zones > commercial areas > cultural and educational areas > parks and green spaces. The distribution of PAHs was characterised by 3-4 ring PAHs in the study areas. The most abundant PAHs were phenanthrene (20.5 %), fluorene (16.7 %), pyrene (12.4 %) and chrysene (Chry) (11.2 %). The mass of the bulk film was composed of organic and inorganic compounds and ranged from 246 to 1,288 mg m(-2). The bulk film thickness varied from 144 to 757 nm in the different functional areas. The ratios of An/178 and Fl/202 and principal component analysis suggested that PAHs came mainly from the mixed sources of fossil fuel, coal and incomplete combustion of biomass. Benzo[a]anthracene (BaA)/Chry is not suitable for use as a tracer for the transmission process of PAHs because of the rapid depletion of BaA in the organic film by photooxidation during daylight hours. The concentration of benzo[a]pyrene equivalent (BaPeq) varied from 21 to 701 ng g(-1), and the major carcinogenic contributors of the 16 PAHs were BaP, DahA, B[b/k]F and InP, accounting for 83 % of BaPeq.

Physicochemical changes in phosphorylase kinase induced by its cationic activator Mg(2+).

For over four decades free Mg(2+) ions, that is, those in excess of MgATP, have been reported to affect a wide variety of properties of phosphorylase kinase (PhK), including its affinity for other molecules, proteolysis, chemical crosslinking, phosphorylation, binding to certain monoclonal antibodies, and activity, which is stimulated. Additionally, for over three decades Mg(2+) has been known to act synergistically with Ca(2+) , another divalent activator of PhK, to affect even more properties of the enzyme. During all of this time, however, no study has been performed to determine the overall effects of free Mg(2+) ions on the physical properties of PhK, even though the effects of Ca(2+) ions on PhK's properties are well documented. In this study, changes in the physicochemical properties of PhK induced by Mg(2+) under nonactivating (pH 6.8) and activating (pH 8.2) conditions were investigated by circular dichroism spectroscopy, zeta potential analyses, dynamic light scattering, second derivative UV absorption, negative stain electron microscopy, and differential chemical crosslinking. The effects of the activator Mg(2+) on some of the properties of PhK measured by these techniques were found to be quite different at the two pH values, and displayed both differences and similarities with the effects previously reported to be induced by the activator Ca(2+) (Liu et al., Protein Sci 2008;17:2111-2119). The similarities may reflect the fact that both cations are activators, and foremost among their similarities is the dramatically less negative zeta potential induced by their binding to PhK.

Immunolocalization of CaMKII and NR2B in hippocampal subregions of rat during postnatal development.

Although the expression of CaMKII and synaptic-associated proteins has been widely studied, the temporospatial distribution of CaMKII and NMDAR subunits in different hippocampal subregions during postnatal development still lacks detailed information. In this study, we used immunofluorescent staining to assess CaMKII and NR2B expressions and the relationship between them in CA1, CA3, and DG of rat hippocampus on postnatal (P) days: P0, P4, P7, P10, P14, P21, P28, and P56. The results showed that from P0 to P56, CaMKII expression increased gradually, while NR2B expression decreased gradually, and the time points of their expression peak differed in CA1, CA3, and DG during postnatal development. Although the expression of CaMKII was negatively correlated with NR2B in CA1 and DG, the coexpression of CaMKII with NR2B existed in CA1, CA3, and DG during postnatal development. Interestingly, after P21, CaMKII expression and the coexpression of CaMKII with NR2B became obvious in the Stratum lucidum of CA3. The specific temporospatial distribution pattern of CaMKII with NR2B might be related to the different physiological functions during postnatal development. Discovery of the alteration of the relationship between expression of CaMKII and NMDAR subunits may be helpful for understanding mechanisms and therapy of neurodegenerative diseases.

Immunoreactivity of Ki-67/ß-tubulin and immunocolocalization with active caspase-3 in rat dentate gyrus during postnatal development.

This study was based on our previous report that the expression of active caspase-3 kept at a high level in dentate gyrus during postnatal development, which is not related to an apoptotic event. We addressed the hypothesis that the active caspase-3 expression may be related to a nonapoptotic role in the regulation of the cell cycle and differentiation or other physiological functions. To confirm this hypothesis, through a temporal investigation from postnatal day (P) 0, 4, 7, 10, 14, 21, 28, to 56, based on immunofluorescent method, we dual labeled active caspase-3 with Ki-67 or ß-tubulin in the dentate gyrus. Our results showed a minority of active caspase-3 positive cells were colabeled with the proliferation marker Ki-67 in stratum moleculare (MOL), granular cell layer (GCL), subgranular zone (SGZ) and polymorphic stratum (POLY) from P0 to P14, and the colabeled cells decreased gradually with age. From P21 to P56, the colocalization of the two proteins was mainly focused on SGZ. There was a positive correlation between the positive cells of active caspase-3 with that of Ki-67. In addition, an extensive colocalization between active caspase-3 and ß-tubulin was observed at all the age groups. There was a strong positive correlation between the intensity of active caspase-3 in GCL with that of ß-tubulin in MOL, GCL and POLY of dentate gyrus and the stratum lucidum of CA3. Our data raised the possibility of a nonapoptotic role of active caspase-3 in dentate gyrus, which may be partly associated with cellular proliferation and differentiation, and also may be related to neurite outgrowth, axonal transport, or dendrite elongation of granular cells during postnatal development.

The glucoamylase inhibitor acarbose is a direct activator of phosphorylase kinase.

Phosphorylase kinase (PhK), an (alphabetagammadelta)(4) complex, stimulates energy production from glycogen in the cascade activation of glycogenolysis. Its large homologous alpha and beta subunits regulate the activity of the catalytic gamma subunit and account for 81% of PhK's mass. Both subunits are thought to be multidomain structures, and recent predictions based on their sequences suggest the presence of potentially functional glucoamylase (GH15)-like domains near their amino termini. We present the first experimental evidence of such a domain in PhK by demonstrating that the glucoamylase inhibitor acarbose binds PhK, perturbs its structure, and stimulates its kinase activity.

Physicochemical changes in phosphorylase kinase associated with its activation.

Phosphorylase kinase (PhK) regulates glycogenolysis through its Ca(2+)-dependent phosphorylation and activation of glycogen phosphorylase. The activity of PhK increases dramatically as the pH is raised from 6.8 to 8.2 (denoted as upward arrow pH), but Ca(2+) dependence is retained. Little is known about the structural changes associated with PhK's activation by upward arrow pH and Ca(2+), but activation by both mechanisms is mediated through regulatory subunits of the (alphabetagammadelta)(4) PhK complex. In this study, changes in the structure of PhK induced by upward arrow pH and Ca(2+) were investigated using second derivative UV absorption, synchronous fluorescence, circular dichroism spectroscopy, and zeta potential analyses. The joint effects of Ca(2+) and upward arrow pH on the physicochemical properties of PhK were found to be interdependent, with their effects showing a strong inflection point at pH approximately 7.6. Comparing the properties of the conformers of PhK present under the condition where it would be least active (pH 6.8 - Ca(2+)) versus that where it would be most active (pH 8.2 + Ca(2+)), the joint activation by upward arrow pH and Ca(2+) is characterized by a relatively large increase in the content of sheet structure, a decrease in interactions between helix and sheet structures, and a dramatically less negative electrostatic surface charge. A model is presented that accounts for the interdependent activating effects of upward arrow pH and Ca(2+) in terms of the overall physicochemical properties of the four PhK conformers described herein, and published data corroborating the transitions between these conformers are tabulated.

Effects of Triton X-100 nanoaggregates on dimerization and antioxidant activity of morin.

Dimerization and antioxidant activity of morin in the Triton X-100 micelles were studied by electronic absorption, ATR-FTIR spectra, cyclic voltammetric, DSC, freeze-fracture TEM, molecular modeling and ab initio quantum calculations. Morin can be solubilized in the Triton X-100 micelles and show selective dimerization in Triton X-100 micelles with different structures. In Triton X-100 spherical micelles, morin always exists in the form of dimer, and in Triton X-100 rodlike micelles, it is always in the form of monomer. The solubilization of morin dimer in Triton X-100 spherical micelles changes the micelle morphology from spherical to cubelike, and the size of the single micelle is also increased, while morin monomer links the Triton X-100 rodlike micelles and forms a kind of network micelle structure with the size of the "rod" unchanged. Solubilized and concentrated in Triton X-100 micelles, morin can protect human serum albumin from the damage induced by hydroxyl radicals effectively and even can form a kind of protein complex with human serum albumin showing more thermal stability.

Combined antioxidant effects of rutin and vitamin C in Triton X-100 micelles.

UV-vis spectra, fluorescence emission spectra and cyclic voltammetric measurements were used to study the influence of Vitamin C on the antioxidant of rutin in Triton X-100 micelles. Rutin can be located in Triton X-100 micelles spontaneously through hydrophobic force, and the binding constant K between rutin and Triton X-100 increases with the rutin concentration. The embedment of two hydroxyl groups on rutin into the more hydrophobic micellar microenvironment makes the oxidation of rutin harder and the radical scavenging activity decrease. With low concentration of Vitamin C, the antioxidant capacity of rutin against hydroxyl radical is enhanced, while that capacity is partly inhibited when the concentration of Vitamin C become higher.

Interaction between flavonoid, quercetin and surfactant aggregates with different charges.

The interactions of flavonoid, quercetin with sodium dodecyl sulfate (anionic surfactant) and cetyltrimethyl ammonium bromide (cationic surfactant) micelles were investigated. The average location site of quercetin in different micelles was determined by the cyclic voltammetry method with the aid of molecular optimization. The interaction parameters of quercetin with micelles of different charges such as binding constant K and normal binding energy DeltaG were calculated. Furthermore, the morphologic change of the SDS and CTAB spherical micelles and rod-like micelles upon their interaction with quercetin was also observed.