Analyzing the Catalytic Mechanism of the Fe-Type Nitrile Hydratase from \u3cem\u3eComamonas testosteroni\u3c/em\u3e Ni1

In order to gain insight into the catalytic mechanism of Fe-type nitrile hydratases (NHase), the pH and temperature dependence of the kinetic parameters kcat, Km, and kcat/Km along with the solvent isotope effect were examined for the Fe-type NHase from Comamonas testosteroni Ni1 (CtNHase). CtNHase was found to exhibit a bell-shaped curve for plots of relative activity vs pH over pH values 4−10 for the hydration of acrylonitrile and was found to display maximal activity at pH ∼7.2. Fits of these data provided a pKES1 value of 6.1 ± 0.1, a pKES2 value of 9.1 ± 0.2 (k′cat = 10.1 ± 0.3 s−1), a pKE1 value of 6.2 ± 0.1, and a pKE2 value of 9.2 ± 0.1 (k′cat/K′m of 2.0 ± 0.2 s−1 mM−1). Proton inventory studies indicate that two protons are transferred in the rate-limiting step of the reaction at pH 7.2. Since CtNHase is stable to 25 °C, an Arrhenius plot was constructed by plotting ln(kcat) vs 1/T, providing an Ea of 33.3 ± 1.5 kJ/mol. ΔH° of ionization values were also determined, thus helping to identify the ionizing groups exhibiting the pKES1 and pKES2 values. Based on ΔH°ion data, pKES1 is assigned to βTyr68 while pKES2 is assigned to βArg52, βArg157, or αSer116 (NHases are α2β2 heterotetramers). Given the strong similarities in the kinetic data obtained for both Co- and Fe-type NHase enzymes, both types of NHase enzymes likely hydrate nitriles in a similar fashion

An Approach to Text Documents Clustering with {n, n-1, ….., 1}-Word(s) Appearance Using Graph Mining Techniques

This paper is about text document clustering with an input of n words. Initially a cluster of all text documents with extension name ".Txt" from m-documents of various types is formed. Then on an input of n-words, the proposed algorithm starts n, n-1, n-2,.....,1 sets of cluster. Each cluster of text documents with the presence of n, n-1, n-2,......,1 word(s) respectively. These n-forms of clustering are treated as documents-words relation and in memory it is represented as un-oriented documents-words incidence matrix. Finally these un-oriented documents-words incidence matrices are represented as bi-partite graphs, since the bi-partite graph has two sets of nodes namely document and word. The proposed algorithm using graph mining techniques was implemented using C++ programming language and the result was satisfactory

Treatment Outcome and Mortality at One and Half Year Follow-Up of HIV Infected TB Patients Under TB Control Programme in a District of South India

There is paucity of data from India on the impact of HIV related immunosuppression in response to TB treatment and mortality among HIV infected TB patients. We assessed the TB treatment outcome and mortality in a cohort of HIV infected TB patients treated with intermittent short course chemotherapy under TB control programme in a high HIV prevalent district of south India. [aOR-4.90, CI (1.85–12.96)]. Factors associated with ‘Death’ were non initiation of ART [aOR-2.80, CI (1.15–6.81)] and CPT [aOR-3.46, CI (1.47–8.14)].Despite the treatment success of 75% the high mortality (30%) in the study group is a matter of concern and needs immediate intervention. Non initiation of ART has emerged as a high risk factor for unfavourable treatment outcome and mortality. These findings underscore the importance of expanding and improving delivery of ART services as a priority and reconsideration of the programme guidelines for ART initiation in HIV infected TB patients

Enzymic synthesis of oligosaccharides by Penicillium chrysogenum Q-176

This article does not have an abstract

Some aspects of the mechanism of thermal acclimation in the earthworm Lampito mauritii

Inorganic ions (Ca, Mg, Na, K, Cl, SO4) and free amino acids of the body fluids of the normal, cold and warm acclimated worms (laboratory as well as seasonal populations) are estimated. Calcium increased and chloride and sodium decreased on both cold and warm acclimation in relation to normal. But magnesium and sulphate and free amino acids increased on warm acclimation whereas potassium increased and magnesium decreased on cold acclimation. Changes in different ions in the same direction are observed in the seasonal populations. Attention is drawn to the adaptive significance of these changes in the different ions during thermal acclimation. Changes in the glycogen, RNA, protein and non-protein nitrogen, and water content in the tissues of normal and acclimated worms are studied. Glycogen increased on warm and cold acclimation, whereas RNA content, protein nitrogen and dry weight of the cold worms increased over normal. No change is observed in non-protein nitrogen on thermal acclimation. The role of these substances and the significance of the changes observed, in the operation of homeostatic mechanism compensating to temperature changes in the metabolic rate of the worms, are also discussed. Changes in the pattern of neurosecretory activity are followed with thermal acclimation and it is shown that the activity of the neurosecretory cells increased on cold and warm acclimation, but the positions of these cells, which are active, are different from normal worms in warm acclimated worms. Studies on the effect of the body fluids of acclimated worms on the tissues of normal and acclimated worms showed that the body fluids of cold acclimated worms increased the respiration of the tissues of normal and warm acclimated worms and vice-versa

On rotations in a pseudo-Euclidean space and proper Lorentz transformations

It is shown that in a general pseudo-Euclidean space En p, 2-flats (planes) passing through the origin of the coordinate system may be classified into six invariant types and explicit formulas for "planar rotations" in these flats are obtained. In the physically important case of the Minkowski World E43, planar rotations are characterized as rotationlike, boostlike and singular transformations and an invariant classification of proper Lorentz transformations into these types is given. It is shown that a general nonsingular proper Lorentz transformation may be resolved as a commuting product of two transformations one of which is rotationlike and the other boostlike while a singular transformation may be written as a product of two rotationlike transformations, each with a rotation angle π. Such a rotationlike transformation with angle π called "exceptional" following Weyl's terminology for similar transformations of SO(3). In all cases, explicit formulas for the angles and planes of rotations in terms of the elements of a given Lorentz matrix are obtained and the procedure yields in a natural manner an explicit formula for the image of L in the D10(D01) representation of SO(3,1) which in turn leads to two more classification schemes in terms of the character χ of L in the D10(D01) and the D1/2O(DO1/2) representations

New starches. Preparation and properties of starch and its fractions of two varieties of groundnuts

The isolation and properties of starch and its fractions from two varieties of groundnuts have been investigated. Starch contents were 13.0 and 18.2% on dry basis of defatted flours. Gelatinization temperatures were 62.0°-66.5°–71.0°C and 63.4°-68.2°-73.2°C and iodine affinities were 5.95 and 6.3 for the two varieties, respectively. Starches from both varieties presented single-staged swelling and solubility behaviour. The amylose content of starch was found to be 30.0% and 28.2%. The molecular weight determinations of amyloses were obtained by gel filtration. The molecular weights of amyloses were approximately 350,000 and 380,000 respectively. The amylopectin fractions from both varieties of groundnuts seem to have molecular weights higher than 20 × 106. Both starches were found to be non-ionic