Dimorphism in Benjaminiella poitrasii: cell wall chemistry of parent and two stable yeast mutants.

In the dimorphic zygomycetous fungus Benjaminiella poitrasii, the cell wall compositions of mycelial phase (M), yeast phase (Y) and its yeast form mutants (Y-2 and Y-5) were studied. Chitosan was abundant in M-phase (26.6%) whereas lesser amounts were present in Y-phase (17.

Ethanol production from cellulose by coupled saccharification/fermentation using Saccharomyces cerevisiae and cellulase complex from Sclerotium rolfsii UV-8 mutant.

Using cellulase/hemicellulase complex of Sclerotium rolfsii UV-8 mutant and Saccharomyces cerevisiae for fermentation, the coupled saccharification/fermentation (CSF) of 15% AT-rice straw was carried out at 40 degrees C, pH 4.5 for the first 24 h and further incubation was performed at 30 degrees C for 72 h. Increasing the amount of cellulase activity from 3-12 IU FPA/g of substrate resulted in increased yields of ethanol from 1.

Mapping the binding site of tissue kallikrein: preparation and testing of all possible substrate analog inhibitors homologous with the sequence of kininogen between Ser386 and Gln392.

Programs aimed at converting peptide inhibitors of proteolytic enzymes into more traditional drug structures require an understanding of the role played by the individual amino acid residues in the inhibitor. To this end, all possible substrate analogues occurring within the sequence Ser386-Pro-Phe-Arg-Ser-Val-Gln392 from bovine kininogen were synthesized and tested as inhibitors of tissue kallikrein (EC 3.4.

Significance of NADP/NAD glutamate dehydrogenase ratio in the dimorphic behavior of Benjaminiella poitrasii and its morphological mutants.

Studies on the levels of glutamate dehydrogenase (GDH), glutamine synthetase, and glutamate synthase were carried out as a function of temperature, nutritional conditions, and the morphological (yeast or mycelium) form of Benjaminiella poitrasii. Since both NAD- and NADP-dependent GDH activities were found in B. poitrasii, the quantitative relation between these two enzymes expressed as the NADP-GDH/NAD-GDH activity ratio (GDH ratio) was studied to evaluate its possible role in the morphogenesis.

Proteinases in fungal morphogenesis.

Fungal morphogenesis is a regulated series of events, leading to changes from one state to another, in which proteolysis could be regarded as one of the controlling functions. Proteinases are essential for the supply of amino acids, selective inactivation of specific growth phase proteins not required during development and for the activation and modification of the enzymes involved in cell wall synthesis. A critical evaluation of the role of proteinases as a biochemical correlate in fungal morphogenesis is discussed.

Histopathological and biochemical effects of gossypol acetate on pituitary-gonadal axis of male albino rats.

Histopathological and biochemical effects of gossypol acetate (GA) on pituitary-gonadal axis were investigated. 10 and 25 mg GA/kg were administered orally to sexually mature adult male Wistar rats for 4 and 5 weeks, respectively. STH and LTH/PRL cells showed no significant changes as compared to those of controls while TSH cells showed hypertrophy, hyperplasia and degranulation in both experimental groups.

α-Glucosidase synthesis in batch and continuous culture ofSaccharomyces cerevisiae.

Glucose prevented maltose utilization in batch culture ofSaccharomyces cerevisiae whereas in a mixed carbohydrate-limited system, maltose and glucose were consumed simultaneously. The specific activity of α-glucosidase depended on the dilution rate as well as the proportion of maltose in the mixture. The chemostat provides a way of reaching the low residual concentrations of glucose in the broth that are necessary to release catabolite repression and permit maltose induction of α-glucosidase.

A systematic approach for determining minimum inhibitory sequence and contribution of individual residues in binding of kininogen fragments to tissue kallikrein.

A systematic approach to evaluate the contribution of individual residues occurring within the sequence Ser386-Pro-Phe-Arg-Ser-Val-Gln392 from bovine kininogen towards binding to tissue kallikrein is developed. Of the 21 sequences which can be formed, no dipeptide and only one tripeptide measurably inhibits the enzyme. Almost 80% of the binding energy of the substrate analogue inhibitors comes from the core sequence Phe-Arg-Ser which occurs between P2 and P1'.

Investigating the stereochemistry of binding to HIV-1 protease with inhibitors containing isomers of 4-amino-3-hydroxy-5-phenylpentanoic acid.

A series of inhibitors containing all possible isomers of 4-amino-3-hydroxy-5-phenylpentanoic acid was synthesized and tested for inhibition of HIV-1 protease. Incorporation of the (3S,4S) isomer of the t-butyloxycarbonyl protected amino acid into the sequence Glu-Phe resulted in a potent inhibitor of HIV-1 protease (Ki = 63 nM). This inhibitor is at least 47-times more potent than the inhibitors containing other isomers of 4-amino-3-hydroxy-5-phenylpentanoic acid, indicating that the (3S,4S) isomer is the preferred isomer for binding to HIV-1 protease.

Substrate analog inhibitors of HIV-1 protease containing phenylnorstatine as a transition state element.

Substrates of HIV-1 protease are classified into three groups (A, B and C) based on the amino acid residues present at P1' and P2' sites. Replacement of the scissile amide bond by phenylnorstatine in representative substrate analog sequences from class A, B and C, yielded inhibitors of HIV-1 protease. Of the twelve inhibitors synthesized in this series, class C substrate analog inhibitors are more potent inhibitors (Ki's 3.

Factors affecting stability of Sclerotium rolfsii UV-8 mutant cellulase complex under saccharification conditions.

Enzyme stability studies in case of Sclerotium rolfsii UV-8 mutant have been investigated under the conditions used for saccharification of cellulose (50 degrees C, pH 4.5, 48 h). Avicelase (measure of exoenzymes) and xylanase were found to be less stable than CMCase (endoglucanase) and beta-glucosidase.

Conformation and inhibitory properties of peptides based on the tissue kallikrein-aprotinin complex.

A series of peptides encompassing the primary binding segment (residues 12-19) of aprotinin has been synthesized and tested for their ability to inhibit porcine pancreatic kallikrein. A minimum sequence of five amino acids spanning residues 12-16 of aprotinin is necessary for inhibition of porcine pancreatic kallikrein. An octapeptide homologous with the binding segment of aprotinin has a Ki-value of 1.

Physiology and nutritional aspects of actinomycetes: an overview.

A review is presented of the nutritional requirements and physiology of actinomycetes, with special emphasis on: (a) selective isolation of unusual forms; (b) colonial morphogenesis and induction of sporulation; (c) biosynthesis of secondary metabolites of value, with particular reference to antibiotics and industrial enzymes. The future potential of actinomycetes as major contributors of useful bioactive metabolites is also indicated.

Dimorphism of Benjaminiella poitrasii: isolation and biochemical studies of morphological mutants.

The yeast-mycelium dimorphism of the genus Benjaminiella poitrasii has been investigated. To understand the mechanism of dimorphism two stable yeast-phase mutants (Y-1 & Y-2) and one slow growing mycelial mutant (M-1) of B. poitrasii were isolated after NTG treatment of parent strain spores and studied for their biochemical characteristics.

Agnihotra - a useful adjunct in recovery of a resistant demotivated smack addict.

AGNIHOTRA is a simple vedic ritual of lightening a pyramid of fire in a small copper pot and giving offering of Ghee & Rice on this fire at the time of sunset and sunrise with enchanting of two mantras. It is reported to enhance the state of tranquility of mind and is reported to be of benefit to those addicted to various types of intoxicants. We used Agnihotra in a young smack addict who was poorly motivated and resisted all efforts to help him even when he got over the physical withdrawal features.

An assay for selective determination of exo-1,4,-beta-glucanases in a mixture of cellulolytic enzymes.

A selective procedure using synthetic substrates for determination of exo-1,4,-beta-glucanases in a mixture of exoglucanases , endoglucanases , and beta-glucosidases is formulated. The heterobiosides , p- nithrophenyl -beta-D- cellobioside ( pNPC ) or p-nitrophenyl-beta-D-lactoside ( pNPL ), were used as selective substrates for the measurement of exoglucanase activity. The exoglucanases (especially cellobiohydrolases , which split off cellobiose units from the nonreducing end of the cellulose chain) specifically act on the agluconic bond (between p-nitrophenyl and the disaccharide moiety) and not on the holosidic bond (between the two glucose units of cellobiose).

High Cellobiase and Xylanase Production by Sclerotium rolfsii UV-8 Mutant in Submerged Culture.

Sclerotium rolfsii UV-8 mutant secretes high levels of cellobiase and xylanase in addition to having high cellulase production. The apparent K(m) and V(max) of cellobiase (grown in NM-2 + 2% corn steep liquor medium) with cellobiose as a substrate were 5.6 mM and 22.

Enhanced Cellulase Production by a Mutant of Sclerotium rolfsii.

A mutant of Sclerotium rolfsii CPC 142 that secretes about two times more filter paper-degrading activity in NM-2 growth medium in submerged cultures than the parent strain was obtained by ultraviolet mutagenesis of crushed sclerotia. The production of endo-beta-glucanase in the mutant was affected to a lesser extent. With the parent strain, the addition of 3% rice bran to NM-2 medium was essential for optimal formation of cellulase, including filter paper-degrading activity.