Cyanide degradation by immobilised fungi

Summary Cyanide hydratase, which converts cyanide to formamide, was induced in mycelia of Stemphylium loti by growth in the presence of low concentrations of cyanide. Mycelia were immobilised by several methods. The most useful system was found to be treatment with flocculating agents. This technique is applicable to a wide range of easily isolated fungi that contain cyanide hydratase.     

Morningness-eveningness preferences,learning approach and academic achievement of undergraduate medical students

ABSTRACT

Several studies have focused on determining the effect of chronotype and learning approach on academic achievement separately indicating that morning types have an academic advantage over the evening types and so have the deep learners over the surface learners. But, surprisingly none have assessed the possible relationship between chronotype and learning approach. So, the current study aimed to evaluate this association and their individual influence on academic performance as indicated by the Cumulative Grade Point Average (CGPA) as well as the effect of their interaction on academic performance. The study included 345 undergraduate medical students who responded to reduced Morningness-Eveningness Questionnaire and Biggs Revised Two-Factor Study Process Questionnaire. Morning types indulged in deep learning while evening types in surface learning. Morning and evening types did not differ on academic performance but deep learners had better academic outcomes than their counterparts. The interaction between chronotype and learning approach was significant on determining academic achievement. Our findings gave the impression that chronotype could have an impact on academic performance not directly but indirectly through learning approaches.     

Lipoxygenase inhibiting and antioxidant oligostilbene and monoterpene galactoside from Paeonia emodi

Paeoninol and paeonin C, oligostilbene and monoterpene galactoside, have been isolated from the methanolic extract of the fruits of Paeonia emodi. Their structures have been assigned on the basis of spectral analysis including 1D and 2D NMR techniques. In addition, 4-hydroxybenzoic acid 3, gallic acid 4 and methyl gallate 5 have also been reported for the first time from this species. Compounds 1 and 2 have displayed potent inhibitory potential against enzyme lipoxygenase in a concentration-dependent fashion with the IC(50) values 0.77 and 99.5 microM, along with ABTS(.+) radical quenching activity with IC(50) values of 147.5 and 498.2 microM, respectively.     

Phenolic glyscosides, a new class of human recombinant nucleotide pyrophosphatase phosphodiesterase-1 inhibitors

Cytotoxicity and kinetic studies of phenolic glycosides, benzoyl salireposide (1) and salireposide (2), isolated from Symplocos racemosa, were performed against phosphodiesterase I enzyme from snake venom and human nucleotide pyrophosphatase phosphodiesterase-1. Lineweaver-Burk and Dixon plots and their secondary replots showed that these compounds are pure non-competitive inhibitors of both enzymes. K(i) Values of compounds 1 and 2 were found to be 360 and 1000 microM, respectively, against human nucleotide pyrophosphatase phosphodiesterase, and 525 and 1100 microM, respectively, against snake venom phosphodiesterase. IC(50) values of compounds 1 and 2 are 90 microM +/- 0.04 and 383 microM +/- 0.03, respectively, against human nucleotide pyrophosphatase phosphodiesterase and 171 microM +/- 0.02 and 544 microM +/- 0.021, respectively, against snake venom phosphodiesterase. Both compounds were found to be nontoxic up to concentration of 500 microM/mL as >90% cells were viable after 3 h of incubation. These compounds are potential candidates for the therapy of arthritis.     

Purification and some properties of galectin-1 derived from water buffalo (Bubalus bubalis) brain

An increasing number of galectins have been found in various animal species, the most abundant of which is galectin-1. The purpose of the present study was to purify and characterize galectin-1 from buffalo brain. We purified the galectin using a combination of ammonium sulphate fractionation and affinity chromatography and the homogeneity was determined by both native polyacrylamide gel electrophoresis (PAGE) and denaturing SDS-PAGE. The molecular weight of the galectin as determined by SDS-PAGE under reducing conditions and by gel filtration column under native conditions was 13.8 and 24.5 kDa, respectively, suggesting a dimeric form of galectin. The most potent inhibitor of the galectin activity was lactose, giving complete inhibition of hemagglutination at 0.8 mM. Galectin showed higher specificity towards human blood group A. Free thiol groups were estimated at a molar ratio of 2.9. The effects of alkylating reagents (iodoacetate and iodoacetamide) on saccharide binding of the galectin were studied. Both alkylating reagents significantly inactivated the activity of the galectin within 20 min. The temperature and pH stability of the galectin were determined. Our findings based on physico-chemical properties, carbohydrate and blood group specificities of the galectin may have future implications in biological and clinical applications.     

A recombinant allosteric lectin antagonist of HIV-1 envelope gp120 interactions

The first, critical stage of HIV-1 infection is fusion of viral and host cellular membranes initiated by a viral envelope glycoprotein gp120. We evaluated the potential to form a chimeric protein entry inhibitor that combines the action of two gp120-targeting molecules, an allosteric peptide inhibitor 12p1 and a higher affinity carbohydrate-binding protein cyanovirin (CVN). In initial mixing experiments, we demonstrated that the inhibitors do not interfere with each other and instead show functional synergy in inhibiting viral cell infection. Based on this, we created a chimera, termed L5, with 12p1 fused to the C-terminal domain of CVN through a linker of five penta-peptide repeats. L5 revealed the same broad specificity as CVN for gp120 from a variety of clades and tropisms. By comparison to CVN, the L5 chimera exhibited substantially increased inhibition of gp120 binding to receptor CD4, coreceptor surrogate mAb 17b and gp120 antibody F105. These binding inhibition effects by the chimera reflected both the high affinity of the CVN domain and the allosteric action of the 12p1 domain. The results open up the possibility to form high potency chimeras, as well as noncovalent mixtures, as leads for HIV-1 envelope antagonism that can overcome potency limits and potential virus mutational resistance for either 12p1 or CVN alone.     

Effect of Pre‐ and Post–Combined Multidoses of Epigallocatechin Gallate and Coenzyme Q10 on Cisplatin‐Induced Oxidative Stress in Rat Kidney

The nephroprotective effect of coenzyme Q10 and epigallocatechin gallate was investigated in rats with acute renal injury induced by a single nephrotoxic dose of cisplatin. Two days prior to cisplatin administration, epigallocatechin gallate and coenzyme Q10 alone and in four different combinations were given for 6 days. The treatment with antioxidants significantly protected the cisplatin‐induced increase in the levels of blood urea nitrogen and serum creatinine. Both the antioxidants alone or in different combinations significantly compensated the increased malondialdehyde and reduced glutathione levels. Moreover, the decrease in the activities of superoxide dismutase, catalase, and glutathione peroxidase and the concentration of selenium, zinc, and copper ions were significantly attenuated in renal tissue. In conclusion, epigallocatechin gallate and coenzyme Q10 are equally effective against cisplatin‐induced nephrotoxicity, whereas the intervention by combining these two antioxidants was found to be highly effective at low doses in attenuating oxidative stress in rat kidney.     

Studies on the role of goat heart galectin-1 as a tool for detecting post-malignant changes in glycosylation pattern

Galectins are mammalian lectins established to play a crucial role in the progression of various cancer types by the virtue of their differential expression in normal and cancerous cells. In the present study, goat heart galectin-1 (GHG-1) was purified and investigated for its potential role in the detection of post-malignant changes in glycosylation pattern. When exposed to superoxide radicals generated from a pyrogallol auto-oxidation system, GHG-1 treated erythrocyte suspension released higher amount of oxyhemoglobin than the unagglutinated erythrocytes. The extent of erythrocyte hemolysis was found to be directly proportional to concentrations of hypochlorous acid. GHG-1 was used to detect the change in the β-galactoside expression pattern in erythrocyte membrane from human donors suffering from prostate and breast cancer. No significant change was observed in the hemolysis of lectin agglutinated erythrocytes collected from pre-operated breast cancer patients, whereas significant increase was observed in normal healthy control and post-operated samples. Findings of this study proclaim GHG-1 as an important tool for the detection of post-malignant changes in glycosylation pattern.Abbreviations: Gal-1, galectin-1; GHG-1, goat heart galectin-1; HOCl, hypochlorous acid; OxyHb, oxyhemoglobin     

Purification,Characterization, Sequencing and Biological Chemistry of Galectin-1 Purified from <Emphasis Type="Italic">Capra hircus</Emphasis> (goat) Heart

A soluble β-galactoside binding 14.5 kDa lectin was purified from the heart of Capra hircus. Its metal independent nature, preferential affinity for β-d-lactose and 90–94% homology with carbohydrate recognition domain of previously reported galectin-1 confirmed its inclusion in galectin-1 subfamily. The secondary structures of the deduced amino acid sequences were generally conserved with previously reported Gal-1. Exposure of the purified protein to varying temperature and pH, oxidant, thiol blocking reagents, denaturants and detergents resulted in significant changes in UV (ultraviolet), fluorescence, CD (circular dichroism) and FTIR (fourier transform infra red) spectra, thus strongly emphasizing the vitality of regular secondary structure of galectins for maintaining their active conformation. Bioinformatics studies corroborated the results obtained in wet lab. Our findings based on physico-chemical properties, oxidative inactivation and structural analysis of the goat heart galectin-1 suggests significant implications in potential biological and clinical applications.     

Synthesis and characterization of mononuclear oxovanadium(IV) complexes and their enzyme inhibition studies with a carbohydrate metabolic enzyme phosphodiesterase I

The increasing interest in vanadium coordination chemistry is based on its well-established chemical and biological functions. A beta-diketonato complex of oxovanadium(IV) is known to be having numerous catalytic applications and also exhibits promising insulin mimetic properties. In continuation of our structure activity relationship studies of metal complexes, we report herein the synthesis and characterization of the vanadium complexes of beta-diketonato ligand system with systematic variations of electronic and steric factors. Two complexes, VO(tmh)(2) (tmh = 2,2,6,6,-tetramethyl-3,5-heptanedione), and VO(hd)(2) (hd = 3,5-heptanedione) were synthesized and characterized by using different spectroscopic techniques. Elemental and mass spectral analysis supports the presence of two beta-diketonato ligands per VO(2+) unit. UV-Vis spectra in different solvents indicate coordination of coordinating solvent molecules at sixth position resulting in red shift of the band I transition. NMR and IR spectra reveal binding of coordinating solvent molecule at vacant sixth position trans to oxo group without releasing beta-diketonato ligands. Enzyme inhibition studies of these and other related oxovanadium(IV) complexes with beta-diketonato ligand system are conducted with snake venom phosphodiesterase I (SPVDE). All of these complexes showed significant inhibitory potential and were found to be non-competitive inhibitors against this enzyme.