γ-Glutamyl transpeptidase from Bacillus pumilus KS 12: decoupling autoprocessing from catalysis and molecular characterization of N-terminal region

Gamma glutamyl transpeptidase from Bacillus pumilus KS12 (GGTBP) was cloned, expressed in pET-28-E. coli expression system as a heterodimeric enzyme with molecular weights of 45 and 20 kDa for large and small subunit, respectively. It was purified by nickel affinity chromatography with hydrolytic and transpeptidase activity of 1.82 U/mg and 4.35 U/mg, respectively. Sequence analysis revealed that GGTBP was most closely related to Bacillus licheniformis GGT and had all the catalytic residues and nucleophiles for autoprocessing recognized from E. coli. It was optimally active at pH 8 and 60°C. It exhibited pH stability from pH 6-9 and high thermostability with t(1/2) of 15 min at 70°C. It had K(m), V(max) of 0.045 mM, 4.35 μmol/mg/min, respectively. Decoupling of autoprocessing by co-expressing large and small subunit in pET-Duet1-E. coli expression system yielded active enzyme with transpeptidase activity of 5.31 U/mg. Though N-terminal truncations of rGGTBP upto 95 aa did not affect autoprocessing of GGT however activity was lost with truncation beyond 63 aa.     

Variations in angiotensin-converting enzyme gene insertion/deletion polymorphism in Indian populations of different ethnic origins

The pattern of angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism in the Indian population is poorly known. In order to determine the status of the polymorphism, young unrelated male army recruits were screened. The population had cultural and linguistic differences and lived in an environment that varied significantly from one region to another. Analysis of the genotype, showed higher frequency of the insertion allele in four of the five groups i.e. I allele frequency was significantly higher (P< 005) in Dogras, Assamese and Kumaonese. The deletion allele frequency was comparatively higher in the fifth group that belonged to Punjab. A correlation was observed between the genotype and enzyme activity. Involvement of a single D allele in the genotype enhanced the activity up to 37.56 ± 313%. The results suggested ethnic heterogeneity with a significant gene cline with higher insertion allele frequency. Such population-based data on various polymorphisms can ultimately be exploited in pharmacogenomics.     

Enhanced thermogenesis in rats byPanax ginseng,multivitamins and minerals

Substances which enhance endurance for physical and mental work and increase non-specific resistance to stress during a prolonged stay in physiologically adverse habitats are called adaptogens.Panax ginseng is well known for its anti-stress and adaptogenic properties. In the present study, adaptogenic activity by the intake of a herbo-vitamin-mineral preparation (HVMP) containingP. ginseng and multivitamin-mineral preparation (MVMP) was evaluated using the cold-hypoxia-restrained (C-H-R) animal model. The aim was to determine whether the cold tolerance and recovery from acute hypothermia mediated byP. ginseng was modified by simultaneous intake of additional vitamins and minerals. Results suggest that the adaptogenic effect of HVMP was more or less the sum total of its two componentsP. ginseng and MVMP. In HVMP,P. ginseng was found to be effective for developing resistance to cooling and MVMP helped in stimulating faster recovery from acute hypothermia.     

Regulation of Brain Nicotinic Receptors by Chronic Agonist Infusion

Several studies have demonstrated that chronic treatment with nicotine elicits an increase in the number of brain nicotinic receptors. To determine whether this effect is elicited by other nicotinic agonists found in tobacco, the effects of chronic infusion with nicotine on brain nicotinic receptors were compared with those after anabasine and lobeline. C57BL/6 mice were infused with saline or equimolar doses (18.5 mumol/kg/h) of nicotine, anabasine, or lobeline for 8 days. Nicotinic receptors, quantified by the binding of [3H]nicotine and [125I]iodo-alpha-bungarotoxin (alpha-[125I]BTX), and muscarinic receptors, quantified by the binding of [3H]quinuclidinyl benzilate ([3H]QNB), were then assayed in eight brain regions. An increase in [3H]nicotine binding was observed in all regions except cerebellum following chronic infusion with nicotine and anabasine, whereas lobeline did not alter the number or affinity of these binding sites. This increase was due to changes in Bmax and not in the affinity of the receptor for the ligand (KD). A slight increase in alpha-[125I]BTX binding was observed in cortex following chronic anabasine infusion. [3H]QNB binding sites were largely unaltered following chronic infusion with any of the nicotinic analogs. The levels of the agonists in the brain were also determined after chronic treatment, and the amounts of lobeline and anabasine were found to be higher than that of nicotine. Thus, the failure of lobeline to elicit changes in nicotine binding is not due to reduced brain concentrations.     

Investigations on the structure of a hemicellulose fraction isolated from the trunk of a young bael (Aegle marmelos) tree

Purified hemicellulose isolated from a young bael (Aegle marmelos) tree with 2.5m sodium hydroxide contained d-xylose and 4-O-methyl-d-glucoronic acid in the molar ratio of 7.43:1; traces of glucose, galactose, rhamnose, and arabinose were also present. The linkages between the monosaccharide units were determined by methylation analysis of a hemicellulose fraction (II A) and carboxyl-reduced, hemicellulose II A, and the results were corroborated by those from periodate oxidation and Smith degradation. The anomeric configurations of the d-xylopyranosyl residues were determined by chromium(VI) trioxide oxidation of the acetylated, carboxyl-reduced hemicellulose, and the aldobiouronic acid obtained from graded hydrolysis was characterized. These experiments clearly revealed the structure of this hemicellulose.     

Interaction between haptoglobin subtypes and AB0 blood groups in a Bengalee population

Blood samples from 621 individuals of a Caste Hindu Population from West Bengal (India) were investigated in an attempt to find out an association between the AB0 blood groups and Haptoglobin (HP) subtypes. AB0 blood grouping was done on the basis of the agglutination test with standard anti-sera. Haptoglobin subtyping only for the HP*1 allele was done by Polyacrylamide Gel Electrophoresis (PAGE). A significant association was found with a significantly lower HP*1S allele frequency in blood group 0 versus other AB0 blood groups. A comparatively higher allele frequency of HP*1S was found in this population sample. An inverse relationship between HP*1S and HP*2 has been revealed in each blood group. It appears that the major portion of HP*1 alleles in the A, B, and AB blood groups belongs to the HP*1S allele compared to that of the 0 blood group.     

Transglutaminase activity is present in highly purified nonsynaptosomal mouse brain and liver mitochondria

Several active transglutaminase (TGase) isoforms are known to be present in human and rodent tissues, at least three of which, namely, TGase 1, TGase 2 (tissue transglutaminase), and TGase 3, are present in the brain. TGase activity is known to be present in the cytosolic, nuclear, and extracellular compartments of the brain. Here, we show that highly purified mouse brain nonsynaptosomal mitochondria and mouse liver mitochondria and mitoplast fractions derived from these preparations possess TGase activity. Western blotting and experiments with TGase 2 knock-out (KO) mice ruled out the possibility that most of the mitochondrial/mitoplast TGase activity is due to TGase 2, the TGase isoform responsible for the majority of the activity ([14C]putrescine-binding assay) in whole brain and liver homogenates. The identity of the mitochondrial/mitoplast TGase(s) is not yet known. Possibly, the activity may be due to one of the other TGase isoforms or perhaps to a protein that does not belong to the classical TGase family. This activity may play a role in regulation of mitochondrial function both in normal physiology and in disease. Its nature and regulation deserve further study.     

The mitogenome of Onchocerca volvulus from the Brazilian Amazonia focus

We report here the first complete mitochondria genome of Onchocerca volvulus from a focus outside of Africa. An O. volvulus mitogenome from the Brazilian Amazonia focus was obtained using a combination of high-throughput and Sanger sequencing technologies. Comparisons made between this mitochondrial genome and publicly available mitochondrial sequences identified 46 variant nucleotide positions and suggested that our Brazilian mitogenome is more closely related to Cameroon-origin mitochondria than West African-origin mitochondria. As well as providing insights into the origins of Latin American onchocerciasis, the Brazilian Amazonia focus mitogenome may also have value as an epidemiological resource.