A novel intermediate in the interaction of thiosemicarbazide with sheep liver serine hydroxymethyltransferase

An unusual intermediate bound to the enzyme was detected in the interaction of thiosemicarbazide with sheep liver serine hydroxymethyltransferase. This intermediate had absorbance maxima at 464 and 440 nm. Such spectra are characteristic of resonance stabilized intermediates detected in the interaction of substrates and quasisubstrates with pyridoxal phosphate enzymes. An intermediate of this kind has not been detected in the interaction of thiosemicarbazide with other pyridoxal phosphate enzymes. This intermediate was generated slowly (t½ = 4 min) following the addition of thiosemicarbazide (200 μM) to sheep liver serine hydroxymethyltransferase (5μM). It was bound to the enzyme as evidenced by circular dichroic bands at 464 and 440 nm and the inability to be removed upon Centricon filtration. The kinetics of interaction revealed that thiosemicarbazide was a slow binding reversible inhibitor in this phase with a kon of 11 M-1 s-1 and a koff of 5 s-1. The intermediate was converted very slowly (k = 4 × 10-5 s-1) to the final products, namely the apoenzyme and the thiosemicarbazone of pyridoxal phosphate. A minimal kinetic mechanism involving the initial conversion to the intermediate absorbing at longer wavelengths and the conversion of this intermediate to the finalp roduct, as well as, the formation of pyridoxal phosphate-thiosemicarbazone directly by an alternate pathway is proposed

EXAMINING THE CRB INDEX AS AN INDICATOR FOR U.S. INFLATION

This paper analyzes historical movements in the commodity futures market and the relationship to inflation. Specifically, the relationship between the Commodity Research Bureau (CRB) Index and United States inflation is investigated. It is said that the relationship between the CRB index and the U.S. inflation rate was greater in the some periods than in another period. Then in recent times the CRB Index has proven to be a reliable early indicator of inflation. As the composition of the United States economy changes, the Commodity Research Bureau must make adjustments in order to provide a viable service.CRB index, Commodities Research Bureau, inflation, Vector Autoregression, Marketing, Public Economics, E00, E30,

Kahler Independence of the G2-MSSM

The G2-MSSM is a model of particle physics coupled to moduli fields with interesting phenomenology both for colliders and astrophysical experiments. In this paper we consider a more general model - whose moduli Kahler potential is a completely arbitrary G2-holonomy Kahler potential and whose matter Kahler potential is also more general. We prove that the vacuum structure and spectrum of BSM particles is largely unchanged in this much more general class of theories. In particular, gaugino masses are still supressed relative to the gravitino mass and moduli masses. We also consider the effects of higher order corrections to the matter Kahler potential and find a connection between the nature of the LSP and flavor effects.Comment: Final version, matches the version published in JHE

Phase transition and hybrid star in a SU(2) chiral sigma model

We use a modified SU(2) chiral sigma model to study nuclear matter at high density using mean field approach. We also study the phase transition of nuclear matter to quark matter in the interior of highly dense neutron stars. Stable solutions of Tolman-Oppenheimer-Volkoff equations representing hybrid stars are obtained with a maximum mass of 1.69 $M_{\odot}$, radii around 9.3 kms and a quark matter core constituting nearly 55-85 % of the star radii.Comment: 19 pages, 9 figures, accepted for Mod. Phys. Letts.

Hepatitis C virus infection is the major cause of severe liver disease in India

The present study describes the status of hepatitis C virus infection in 167 patients with severe forms of liver diseases in India. The anti-HCV positivity rate was recorded as 43%, 47% and 42% in patients with FHF, SAHF and CAH respectively. HBV and HCV coinfection was recorded in 28% of FHF, 43% of SAHF and 75% of the CAH cases. Superinfection of HCV in HBsAg carriers was recorded in 54% cases of FHF, 60% of SAHF and 42% of the CAH. None of these 167 patients was positive of HAV-IgM. Further, 27.7% of FHF, 26.4% of SAHF and 15.2% of CAH cases were neither HBV nor HCV markers positive. These can be labelled as non-A, non-B and nonC infections

Binary and ternary complexes of nickel(II) with 2-aminomethylbenzimidazole and salicylaldehyde: kinetic and equilibrium studies

The complexation of NiII with 2-aminomethylbenzimidazole (L) has been investigated at 20–40 °C, I= 0.30 mol dm-3. Both monoprotonated and unprotonated ligands bind the metal ion to form [NiL]2+. and the rate and activation parameters for the formation and acid-catalysed dissociation of this chelate are calculated. In the presence of Salicylaldehyde (Hsal), a mixed-ligand complex. [NiL(sal)]+, is also formed as an intermediate which further condenses to the Schiff-base complex, [NiL']+[HL'=N-(benzimidazol-2-ylmethyl)salicylideneimine]. The kinetics of the fast ternary complex formation and its slow intramolecular transformation to the Schifi base complex have been investigated at 25 °C. The presence of L in the co-ordination sphere of Ni2+ enhances the dissociation of [NiL(sal)]+ to [NiL]2+ and sal– with respect to [Ni(Sal)]+, as evidenced by the stability constants of [NiL(sal)]+ and [Ni(sal)]+. Calculations based on the values of ΔS° for the ionisation of H2L2+ and the formation of [NiL]2+combined with S [> with combining macron]aq°(H+) and S[> with combining macron]aq°(Ni2+) data yielded the values S[> with combining macron]aq°(H2L2+)–S[> with combining macron]aq°(L)= 110, S[> with combining macron]aq°(L)–S[> with combining macron]aq°(HL+)=–116 and S[> with combining macron]aq°([NiL]2+)–S[> with combining macron]aq°(L)=–294 J K−1 mol−1, which presumably reflect the varying solvent-ordering effects of L, HL+, H2L2+ and [NiL]2+

Complex formation between nickel(II) and some pentamine (substituted salicylato)cobalt(III) ions

The kinetics of reversible complexation of NiII with pentamine(substituted salicylato)cobalt(III) ions, [Co(N5){O2CC6H3(X)OH}]2+[N5= 5NH3, (en)2(NH3)(cis isomer, en = ethane-1,2-diamine) or tetren (tetraethylenepentamine), X = 3-NO2; N5= 5NH3, X = 5-NO2], was investigated by the stopped-flow technique at 15–35 °C, pH 5.70–6.90 and I= 0.30 mol dm−3(ClO4−). The formation of [(Co(N5){O2CC6H3(X)O}Ni]3+ occurs via the reaction of [Ni(OH2)6]2+ with the phenoxide form of the cobalt(III) substrates. The rate and activation parameters have been determined for the formation and dissociation of the binuclear species in which nickel(II) is chelated by the salicylate moiety. The data are consistent with and Id mechanism. The rate constant for spontaneous dissociation of the binuclear species to the reacting partners is sensitive to the nature of the pentamine moiety and decreases in the sequence tetren > (en)2(NH3)− 5NH3. The acid-catalysed dissociation of cis-[(en)2(NH3)Co{O2CC6H3(NO2−3)O}Ni]3+ conforms to a two-step process

Significance of anti-pre-S antibodies in patients with fulminant hepatic failure

Anti-pre-S antibody was tested in 38 sera from patients with fulminant hepatitis (positive for HBsAg and/or IgM anti-HBc) using a specific solid phase enzyme linked immunosorbent assay (ELISA). Anti-pre-S activity was detected in 50 percent sera samples positive for HBsAg but negative for IgM antiHBc. There were 12.5% sera positive for both HBsAg as well as IgM anti-HBc and 75% sera negative for HBsAg but positive for IgM anti-HBc. The prevalence of HBV-specific DNA-polymerase activity was high in all the three groups whereas anti-HBs positivity was low. Anti-pre-S activity was observed both in the presence as well as in the absence of DNA-polymerase activity. High-anti-pre-S level in fulminant hepatitis B patients was assumed to be implicated in the fast clearance of HBsAg from circulation

Hybrid Formalism, Supersymmetry Reduction, and Ramond-Ramond Fluxes

The supersymmetric hybrid formalism for Type II strings is used to study partial supersymmetry breaking in four and three dimensions. We use worldsheet techniques to derive effects of internal Ramond-Ramond fluxes such as torsions, superpotentials and warping.Comment: Harvmac. No figure