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PubMedDate not supplied

[O-glycosylhydrolases of marine filamentous fungi. beta-1,3-Glucanases of Trichoderma aureviride].

The ability to produce extracellular O-glycosylhydrolases was studied in 14 strains of marine filamentous fungi sampled from bottom sediments of the South China Sea. The following activities were detected in the culture liquids of the fungi: N-acetyl-D-glucosaminidase, D-glucosidase, D-galactosidase, beta-1,3-glucanase, amylase, and pustulanase. beta-1,3-Glucanases were isolated by ultrafiltration, hydrophobic interaction chromatography, and ion-exchange chromatography, and their properties were studied. Data on products of enzymatic digestion of laminaran, absence of transglycosylation activity, and the pattern of action of natural inhibitors confirmed that beta-1,3-glucanase belonged to the exo type. Inhibitor analysis demonstrated the role of a thiol group and tryptophan and tyrosine residues in the catalytic activity.

Chromatography, Ion Exchange↗
PubMed2004

[Cloning and expression of xyn III from genomic DNA of Trichoderma reesei QM9414 by overlap-PCR].

After the cell enters into its programmed cell death, xylanases from grass plants gradually matured through its N-terminal and C-terminal sequence been cut by acid proteases several times. They could not be expressed by conventional protein expression system. Search the GenBank database, xynIII from a mutant of T. reesei QM9414(ATCC26921)was found. It is similar to grass plants' xylanase in their families and structures. It couldn't express in T. reesei QM9414, but its gene exist in genomic DNA as one copy. Through overlap-PCR method, 4 exons of xynIII were cloned, sequenced, spliced, and the whole cDNA of mature xynIII was acquired. The cDNA was inserted into pETBlue-2 vector and transformed into E. coli DE3 pLacI cell. Xyn III could be expressed in the transformed cell under the conditions of 37 degrees C, 1 mmol/L IPTG induced for 3h. Low temperature (15 degrees C), long time(64h) induction(0.2 mmol/L IPTG) could enhance xynIII activity.

Cloning, Molecular↗
PubMed2003

[Integration and expression of beta-endoglucanase I from Trichoderma reesei in brewing yeast].

An integration plasmid pA15-PET for expression and secretion of beta-Endoglucanase I (EG I ) in yeast was constructed by insertion of EG I cDNA between yeast alcohol dehydrogenase promoter and terminator region. The plasmid contained part of yeast rDNA sequence, which was used as a homologous fragment for integration. The EG I cDNA was introduced into an engineered brewing yeast BE9711 containing alpha-acetolactate decarboxylase (alpha-ALDC) encoding gene and integrated onto its rDNA sequence of chromosomal DNA by co-transformation of pA15-PET and a YEP type plasmid pA15TXR carrying G418 resistance. The stable engineered brewing yeast expressing intracellulase alpha-ALDC and extracellular EG I simultaneously were obtained.

Alcohol Dehydrogenase↗
PubMed2005

[Expression of endo-beta-mannanase gene from Trichoderma reesei in Pichia pastoris].

Complete mannanase gene with two introns was cloned from Trichoderrna reesei by PCR. The two introns were then removed by overlap extension PCR. The gene encoding the mature mannanase protein was inserted into the expression vector pPIC9K, downstream of a alpha-factor signal peptide sequence. The resultant recombinant vector was named pM242. After linearized with Sac I , pM242 was transformed to Pichia pastoris GS115 by electroporation. After screening, the recombinant strain Gpmf25 that expresses the secretory protein at high level was obtained. The activity of the recombinant mannanase reached 12.5 IU/mL. Optimum pH and temperature for the recombinant enzyme were 5.0 and 80 degrees C, respectively. The enzyme was stable at pH 5.0-6.0 and maintained over 50% of original activity after incubation at 70 degrees C for 30 min.

Fungal Proteins↗
PubMed2006

Affinity foam fractionation of Trichoderma cellulase.

Cellulase could not be selectively collected from fermentation broth by simple foam fractionation, because of the presence of other more surface-active compounds. A new approach of affinity foam fractionation was investigated for improvement. A hardwood hydrolysate (containing cellulose oligomers, substrates to cellulase) and two substrate analogs, i.e., carboxymethyl cellulose (CMC) and xylan hydrolysate, were added before the foaming process. The substrates and substrate analogs were indeed found to bind the cellulase selectively and form more hydrophobic complexes that partition more readily onto bubble surfaces. In this study, the effects of the type and concentration of substrate/analog as well as the presence of cells at different growth stages were examined. The foam fractionation properties evaluated included foaming speed, foam stability, foamate volume, and enrichment of filter paper unit (FPU) and individual cellulase components (i.e., endoglucanases, exoglucanases, and beta-glucosidases). Depending on the broth and substrate/analog employed, the foamate FPU could be more than fourfold higher than the starting broth FPU. Addition of substrate/analog also deterred the enrichment of other extracellular proteins, resulting in the desired cellulase purification in the foamate. The value of E/P (enzyme activity-FPU/g/L of proteins) in the foamate reached as high as 18, from a lactose-based fermentation broth with original E/P of 5.6. Among cellulase components, exoglucanases were enriched the most and beta-glucosidases the least. The study with CMC of different molecular weights (MW) and degrees of substitution (DS) indicated that the CMC with low DS and high MW performed better in cellulase foam fractionation.

Cell Culture Techniques↗
PubMedDate not supplied

[A spectrophotometric method for determining the concentration of L-lysine using L-lysine-alpha-oxidase from Trichoderma sp. and 3,3',5,5'-tetramethylbenzidene dihydrochloride].

A simple and relatively sensitive procedure was developed for determination of L-lysine at 3-30 mmole/L concentration. The procedure does not involve the carcinogenic compound o-dianisidine. L-lysine alpha-oxidase catalyzed oxidative deamination of L-lysine with O2 consumption and formation of H2O2, NH3 and alpha-keto-epsilon-aminocaproic acid. Horseradish peroxidase and a non-carcinogenic compound 3,3,5,5'-tetramethylbenzidine dihydrochloride as an electron donor were used in determination of H2O2 formed. The procedure developed enabled also to measure the L-lysine alpha-oxidase activity at the enzyme concentrations of 10-500 ng/ml. The only limitation of the procedure is relatively low pH-values of the reaction medium.

Amino Acid Oxidoreductases↗
PubMedDate not supplied

[Improved method of purification of L-lysine-alpha-oxidase from the fungus Trichoderma sp].

Relatively rapid procedure was developed for isolation and purification of the antitumor enzyme L-lysine alpha-oxidase. The procedure involved three steps instead of six or four steps described previously, with a yield of 64.4%. The homogenous preparation was obtained as shown by gel electrophoresis and ultracentrifugation. The antitumor activity of the enzyme both in vivo and in vitro is under investigation.

Amino Acid Oxidoreductases↗
PubMed1980

[Purification and properties of low molecular weight endoglucanase of the cellulase complex from Trichoderma koningii].

A homogenous low molecular weight 1,4-beta-glucan glucanohydrolase (endoglucanase) has been isolated from a crude commercial preparation of cellokoningine P10X of T. koningii origin. The molecular weight of the enzyme as determined by polyacrylamide gel electrophoresis is 13 000. The endoglucanase was obtained as a lyophylized preparation free of the cellobiase activity. It was shown that cellobiose or methylcellobioside activate the effect of the low molecular weight endoglucanase (measured by the viscometric technique with respect to CMC hydrolysis) and at the same time almost completely suppress the activity of high molecular weight endoglucanases from the sane source. A detailed kinetic study of the effects showed that the low molecular weight enzyme is activated by a transglycosylation mechanism, where cellobiose acts as an added nucleophile. The activation is 6-fold at saturating concentrations of cellobiose (Ks = 15 mM). It was shown that diverse kinetic behaviour of cellobiose which can act both as activatory and inhibitor for endoglucanases from different sources can be explained, firstly, by different ratios of low to high molecular weight endoglucanases in the cellulase complexes, and, secondly, by their ability to catalyze transglycosylation reactions, which, in turn, results in a transfer of reducing end groups of the reaction products onto cellobiose as an added nucleophile.

Cellobiose↗
PubMed1996

Solubilization and one-step purification of mannosylphosphodolichol synthase from Trichoderma reesei.

Mannosylphosphodolichol synthase (MPD-synthase) (EC 2.4.1.830) catalyzing formation of MPD from GDPMan and dolichylphosphate (PD) has been purified from T. reesei cellular membranes almost to homogeneity. Selective solubilization of the enzyme was followed by one step purification on Phenyl-Sepharose column. SDS/ PAGE of the purified enzyme fraction revealed the presence of a protein band of 31 kDa corresponding to the apparent molecular mass of the MPD-synthase purified from S. cerevisiae [Babczinski, P. et al. (1980) Eur. J. Biochem. 105, 509-515; Haselbeck A. (1989) Eur. J. Biochem. 181, 663-668]. During solubilization, the enzyme was stabilized by the presence of a lipophilic substrate dolichylphosphate and phospholipids as well as by protease inhibitors. The Phenyl-Sepharose purified enzyme had an absolute requirement for dolichylphosphate and was activated by cAMP dependent protein kinase.

Chromatography, Gel↗
PubMed1998

Tryptophan residues in alpha-galactosidase from Trichoderma reesei.

Tryptophan residues in alpha-galactosidase were modified with bromosuccinimide. The fact that galactose, a specific inhibitor of alpha-galactosidase, does not prevent this modification demonstrates that tryptophan residues are not located in galactose binding sites. Analysis of the inactivation kinetics revealed two groups of Trp residues (8.5 and 7.5 residues) with different accessibility for N-bromosuccinimide. We studied specific quenching of alpha-galactosidase fluorescence resulting from modification of an sulfhydryl group in the active site of the enzyme with Hg2+ and Ag+ ions. The specific quenching is due to conformational changes of the enzyme. Forster's radii were determined for various protein--chromophore complexes. Dynamic quenching of alpha-galactosidase fluorescence was investigated. To describe abnormal dynamic quenching in alpha-galactosidase, a modification of the Stern--Volmer equation is suggested.

Bromosuccinimide↗