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Hydrolase activity of (enzymograms, biotypes) in Geotrichum candidum, one of the poorly described pathogenic fungi, was studied 81 strains were isolated from oral cavity and faeces of patients with gastrointestinal tract disorders. Axenic strains were differentiated with API 20C Aux and API ZYM tests. Then, enzymograms and biotypes were determined for all strains based on the activity of 19 hydrolases. High variability of enzymograms (17 different types) was found. The highest activity was noted in case of: e2-alkaline phosphatase, e6-lecucine arylamidase, e11-acid phosphatase. E5-lipase. e7-valine arylamidase, e12 - naphtol-AS-BI-phosphohydrolase and e17-β-glucosidase were used for biotyping procedures. Our own system of biotyping of 81 strains of G. candidum was based on the mathematical binominal distribution formula (1 : 4 : 6 : 4: 1) – all; ,,+”;one „-”, three „+”; two „-”,two „+”; three ,,-”,one ,,+”; all „-”. We have found: A (11.1 ± 3.5%), B1 (6.17 ± 2.67%). B2 (1.23 ± 1.22%), B4 (4.94 ± 2.41%), C1 (1.23 ±1.22%), C3 (63.0 ± 5.4%), D2 (9.88 ±3.31%), D3 (2.47 ± 1.72%). Among all strains from 8 various biotypes of G. candidum.
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Similar patterns of hydrolases were observed in three species representing two genera of entomopathogenic nematodes: Steinernema affinis, S. feltiae, and Heterorhabditis zealandica. The same enzymes were present in the studied nematodes but they differed in the level of activity of individual sub-classes of enzymes. A higher activity of esterases and proteolytic enzymes could be observed for H. zealandica than for S. affinis and S. feltiae. On the other hand, the activity of glycosidases in steinernematids was generally much higher than in H. Zealandica.
Investigated was the effect of intraperitoneal injections (twice daily for seven consecutive days) of reduced glutathione (GSH) on activity of selected lysosomal hydrolases (alanine aminopeptidase, leucine aminopeptidase, cathepsins D and L, acid phosphatase and N-acetyl-β-D-glucosaminidase) in lysosomal, microsomal and cytosol fractions of mouse kidney. Most notable effect of exogenous GSH on the activity of the enzymes considered was observed in lysosomal, while the least in microsomal fraction. After a series of GSH injections the activity of enzymes increased significantly mainly In lysosomal fraction. It is assumed that the increase in activity of lysosomal enzymes following the GSH injections results from a physiological response of renal cells to this antioxidant.
Adenosine 5'-phosphoramidate (NH2-pA) is a rare natural nucleotide and its biochemistry and biological functions are poorly recognized. All organisms have proteins that may be involved in the catabolism of NH2-pA. They are members of the HIT protein family and catalyze hydrolytic splitting of NH2-pA to 5'-AMP and ammonia. At least five HIT proteins have been identified in mammals; however, the enzymatic and molecular properties of only Fhit and Hint1 have been comprehensively studied. Our study focuses on the Hint2 protein purified by a simple procedure to homogeneity from sheep liver mitochondrial fraction (OaHint2). Hint1 protein was also prepared from sheep liver (OaHint1) and the molecular and kinetic properties of the two proteins compared. Both function as homodimers and behave as nucleoside 5'-phosphoramidate hydrolases. The molecular mass of the OaHint2 monomer is 16 kDa and that of the OaHint1 monomer 14.9 kDa. Among potential substrates studied, NH2-pA appeared to be the best; the Km and kcat values estimated for this compound are 6.6 µM and 68.3 s-1, and 1.5 µM and 11.0 s-1 per natively functioning dimer of OaHint2 and OaHint1, respectively. Studies of the rates of hydrolysis of different NH2-pA derivatives show that Hint2 is more specific towards compounds with a P-N bond than Hint1. The thermostability of these two proteins is also compared.
Celem pracy było zbadanie wpływu porostu ziarna na zmiany aktywności enzymów amylolitycznych i proteolitycznych oraz określenie możliwości wykorzystania mąki z ziarna porośniętego w piekarstwie, po zastosowaniu witaminy C i glutenu witalnego jako polepszaczy. W próbach mąk wzorcowych i z ziarna porośniętego oznaczono: liczbę opadania, poziom azotu niebiałkowego, ogólną aktywność amylaz i proteaz oraz przeprowadzono analizę farinograficzną. Badania zakończono próbnym wypiekiem laboratoryjnym. Aktywność enzymów hydrolitycznych wzrosła w każdej próbie mąki z ziarna porośniętego. W mące z ziarna odmiany Korweta aktywność amylaz zwiększyła się o 80%, a z odmian Alba i Sakwa odpowiednio o 42 i 31%. Poziom aktywności proteaz również wzrósł znacząco, największy przyrost o 78% odnotowano w mące z ziarna odmiany Korweta. Stwierdzono zależność pomiędzy cechami fizycznymi ciasta i wielkością aktywności hydrolaz. Próba mąki z porośniętego ziarna Korweta charakteryzowała się najwyższym przyrostem aktywności amylaz i proteaz, jednocześnie jej parametry farinograficzne w największym stopniu uległy pogorszeniu. Odnotowano korzystny wpływ preparatów polepszających na pieczywo uzyskane z mąki z ziarna porośniętego.
Arabidopsis thaliana AtNUDT7 Nudix pyrophosphatase hydrolyzes NADH and ADP-ribose in vitro and is an important factor in the cellular response to diverse biotic and abiotic stresses. Several studies have shown that loss-of-function Atnudt7 mutant plants display many profound phenotypes. However the molecular mechanism of AtNUDT7 function remains elusive. To gain a better understanding of this hydrolase cellular role, proteins interacting with AtNUDT7 were identified. Using AtNUDT7 as a bait in an in vitro binding assay of proteins derived from cultured Arabidopsis cell extracts we identified the regulatory protein RACK1A as an AtNUDT7-interactor. RACK1A-AtNUDT7 interaction was confirmed in a yeast two-hybrid assay and in a pull-down assay and in Bimolecular Fluorescence Complementation (BiFC) analysis of the proteins transiently expressed in Arabidopsis protoplasts. However, no influence of RACK1A on AtNUDT7 hydrolase catalytic activity was observed. In vitro interaction between RACK1A and the AGG1 and AGG2 gamma subunits of the signal transducing heterotrimeric G protein was also detected and confirmed in BiFC assays. Moreover, association between AtNUDT7 and both AGG1 and AGG2 subunits was observed in Arabidopsis protoplasts, although binding of these proteins could not be detected in vitro. Based on the observed interactions we conclude that the AtNUDT7 Nudix hydrolase forms complexes in vitro and in vivo with regulatory proteins involved in signal transduction. Moreover, we provide the initial evidence that both signal transducing gamma subunits bind the regulatory RACK1A protein.
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