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PubMed1994

Fungal metabolites. XIII. Isolation and structural elucidation of new peptaibols, trichodecenins-I and -II, from Trichoderma viride.

Three new groups of peptaibols, trichodecenins, trichorovins and trichocellins, have been isolated from conidia of the fungus, Trichoderma viride. The structures of trichodecenins-I and -II were established by positive-ion fast-atom bombardment, collision-induced dissociation mass spectrometry and two-dimensional NMR spectroscopy. Trichodecenins-I and -II have a (Z)-4-decenoyl group, six amino acid residues and a leucinol moiety in the molecules. Trichodecenin-II was synthesized by the solution-phase method.

Amino Acid Sequence↗

PubMed1995

Studies on metabolites of mycoparasitic fungi. IV. Minor peptaibols of Trichoderma koningii.

Three minor peptaibols, trichokonins (TKs)-Ia, Ib, and IX, were obtained from the culture broth of Trichoderma koningii Oudemans. Primary structures of these peptaibols were elucidated by ion-spray ionization mass spectrometry (ISI-MS) including the collision-induced dissociation (CID) technique together with two-dimensional nuclear Overhauser enhancement spectroscopy (NOESY).

Alamethicin↗

PubMed1995

Studies on metabolites of mycoparasitic fungi. II. Metabolites of Trichoderma koningii.

Four peptaibols, named trichokonins (TKs) V, VI, VII, and VIII, were isolated from the culture broth of Trichoderma koningii Oudemans. Primary structures of these peptaibols were elucidated by electrospray ionization mass spectrometry (ESI-MS), FAB-MS, and collision-induced dissociation (CID) techniques along with nuclear Overhauser enhancement spectroscopy (NOESY).

Alamethicin↗

PubMed1995

Fungal metabolites. XVIII. New membrane-modifying peptides, trichorozins I-IV, from the fungus Trichoderma harzianum.

New membrane-modifying peptides, trichorozins I-IV, have been isolated from conidia of the fungus Trichoderma harzianum. Their amino acid sequences were clearly determined by spectrometric methods and, furthermore, they were synthesized by the solution-phase method. Trichorozins are a family of the class of peptaibols and are composed of 11 residues including an amino alcohol. Trichorozins exhibited voltage-dependent ion channel-like activity in lipid bilayers.

Amino Acid Sequence↗

PubMed1995

Fungal metabolites. XIX. Structural elucidation of channel-forming peptides, trichorovins-I-XIV, from the fungus Trichoderma viride.

Trichorovins (TV)-I-XIV are new antibiotic peptides obtained from conidia of the fungus Trichoderma viride. The peptide mixture of TVs was repeatedly fractionated by preparative HPLC until individual TVs showed a single peak on their analytical HPLC chromatograms. Nevertheless, FAB-MS or NMR indicated that each of TVs-I-XIV was composed of at least two components. We attempted to elucidate their structures within the fractions by electrospray ionization (ESI)-MS, FAB-MS, FAB-MS/MS and NMR. TVs generally have molecular weights of approximately 1100-1200 Da, and are characterized by an acetylated N-terminus, the presence of an aminoalcohol, e.g. leucinol, isoleucinol or valinol, at the C-terminus, and eleven residues including three alpha-aminoisobutyric acids in the molecule. Thus, it was determined that TVs belong to the class of peptaibols.

Amino Acid Sequence↗

PubMed1996

Studies on metabolites of mycoparasitic fungi. V. Ion-spray ionization mass spectrometric analysis of trichokonin-II, a peptaibol mixture obtained from the culture broth of Trichoderma koningii.

The sequence of a peptide, trichokonin-II (TK-II), obtained from the culture broth of Trichoderma koningii OUDEMANS, was examined by ion-spray ionization mass spectrometry (ISI-MS), including the collision-induced dissociation (CID) technique. TK-II was concluded to be a mixture of three peptaibols, TK-IIa, TK-IIb, and TK-IIc.

Alamethicin↗

PubMed1992

An Avicel-affinity site in an Avicel-digesting exocellulase from a Trichoderma viride mutant.

A single form of exo-type cellulase (Exo I; MW, 65,000), purified from a Trichoderma viride protease-depressed mutant, HK-75, digested Avicel to cellobiose exowise, and hydrolyzed cellotriose, cellotetraose, and cellopentaose in the strict manner of splitting off by cellobiose units. Exo I, however, hydrolyzed cellohexaose by both cellobiose and cellotriose units. Exo I was proteolyzed by papain into two fragments; GPExo (MW, 9,000) and Exo I' (MW, 56,000). The GPExo intensively adsorbed onto Avicel but did not hydrolyze it. Exo I' had nearly identical activity to that of intact Exo I toward cellooligosaccharides but was almost inert to Avicel in digestion and adsorption. Sequence analysis of N-terminal and C-terminal amino acids showed that GPExo was between Gly435 and Leu496 and Exo I' between Glu1 and Gly434 in Exo I. Exo I therefore consists of two domains, one for adsorption to Avicel, as demonstrated by the Avicel-affinity site, GPExo and the other for the cleavage of glycosidic linkages as demonstrated in Exo I'.

Adsorption↗

PubMed1995

Koninginin C: a biologically active natural product from Trichoderma koningii.

Koninginin C, a congener of koninginins A and B, was isolated from Trichoderma koningii fermented on a shredded wheat medium. The compound inhibited the growth of etiolated wheat coleoptiles by 100% at 10(-3) M. It was a fine, white crystalline substance with a molecular formula of C16H28O4 and a melting point of 70-72 degrees C.

Benzoxepins↗

PubMed1996

Cloning of a gene encoding a putative carbon catabolite repressor from Trichoderma reesei.

We report the cloning and sequencing of a Trichoderma reesei genomic DNA clone that encodes a protein similar to the Aspergillus CREA, a carbon catabolite repressor. The deduced amino acid sequence predicts a zinc finger protein of 402 amino acids in length. The overall amino acid sequence of the T. reesei CREA shows about 52% similarity with Aspergillus CREAs.

Amino Acid Sequence↗

PubMed1998

Substrate specificity of the alpha-L-arabinofuranosidase from Trichoderma reesei.

The precise substrate specificities of an alpha-L-arabinofuranosidase from Trichoderma reesei were investigated. The enzyme released arabinose at appreciable rates from p-nitrophenyl-alpha-L-arabinofuranoside, O-alpha-L-arabinofuranosyl-(1-->3)-O-beta-D-xylopyranosyl-(1-->4) -D-xylopyranose (A1X2), arabinan, arabinoxylan, arabinogalactan, debranched-arabinan and gum arabic, but not from O-beta-D-xylopyranosyl-(1-->4)-[O-alpha-L-arabinofuranosyl-(1-->3)] -O-beta-D-xylopyranosyl-(1-->4)-D-xylopyranose (A1X3) or O-beta-D-xylopyranosyl-(1-->2)-O-alpha-L-arabinofuranosyl -(1-->3)-O-beta-D-xylopyranosyl-(1-->4)-O-beta-D-xylopyranosyl-(-->4) -D-xylopyranose (A1X4). The enzyme hydrolyzed methyl 2-O-, methyl 3-O- and methyl 5-O-alpha-L-arabinofuranosyl-alpha-L-arabinofuranosides to arabinose and methyl alpha-L-arabinofuranoside with the order of hydrolysis being: (1-->5)- > (1-->2)- > or = (1-->3)-linkages. The enzyme hydrolyzed the (1-->3)-linkage faster than the (1-->5)-linkage of methyl 3,5-di-O-alpha-L-arabinofuranosyl-alpha-L-arabinofuranoside. The degree of conversion of arabinan and debranched-arabinan to monosaccharides by the enzyme was 33.0% and 9.1%, respectively. The alpha-L-arabinofuranosidase preferentially cleaved the arabinosyl side-chain from the arabinan rather than the terminal arabinosyl residue of the arabinan backbone.

Carbohydrate Conformation↗

PubMed1999

Heterologous expression and characterization of endoglucanase I (EGI) from Trichoderma viride HK-75.

Endoglucanase I (EGI) secreted from Trichoderma viride HK-75 has a unique transglycosylation activity. The genomic and cDNA clones encoding EGI (egl1) of T. viride HK-75 were isolated and characterized. The coding region of egl1, composed of 1392 bp, was found to encode a polypeptide of 464 amino acids that has extensive similarity (93.8%) with EGI of T. reesei. Expression of the egl1 gene in E. coli as a fusion protein (with N-terminal thioredoxin and C-terminal histidine tag) led to a large production of a nonglycosylated protein of 62.5 kDa. However, it formed an insoluble inclusion body. Upon denaturation with 8 M urea followed by dialysis and successive purification, the enzymatically active recombinant EGI (rEGI) was obtained at a level as high as 18.3 mg/l of 1,000 ml of culture. The rEGI had 67.8% activity for carboxymethyl cellulose (CMC), compared to native EGI (nEGI). The optimum pH and optimum temperature of rEGI were lower than those of nEGI by 0.5 and 5 degrees C, respectively. The rEGI also had narrower CMCase ranges than nEGI in pH and temperature stabilities. However, the catalytic and transglycosylation abilities against cellotriose of rEGI were comparable to those of nEGI. These results suggest that the glycosylation is important for the stabilities of EGI but not critical for the essential enzymatic capacity.

Amino Acid Sequence↗

PubMed2000

Novel fungal metabolites, demethylsorbicillin and oxosorbicillinol, isolated from Trichoderma sp. USF-2690.

The novel compounds, demethylsorbicillin (1) and oxosorbicillinol (2), were isolated from a fermentation broth of Trichoderma sp. USF-2690. The structures of these compounds, which were determined from spectroscopic evidence, suggest the possibility that methylation at C-6 and oxidation at C-1 and C-6 of sorbicillin were controlled in the early polyketide stage before the formation of oxidized sorbicillin dimers. In a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging assay, 2 gave an ED50 value of 87.7 microM.

Anti-Bacterial Agents↗

PubMed2000

Hybridization and breeding of the benomyl resistant mutant, Trichoderma harziantum antagonized to phytopathogenic fungi by protoplast fusion.

A diploid strain obtained from heterokaryons of Trichoderma harzianum by protoplast fusion grew on minimal medium containing 100ppm benomyl. This strain inhibited the growth of the phytopathogenic fungus Fusarium oxysporum f. sp. raphani on paired cultures and also protected against radish yellows and a drop in germination induced by F. oxysporum f. sp. raphani.

Benomyl↗

PubMed2001

Purification and some properties of a beta-glucosidase from Trichoderma harzianum type C-4.

Type C-4 strain of Trichoderma harzianum was isolated as a microorganism with high cellulolytic activity. Beta-glucosidase is involved in the last step of cellulose saccharification by degrading cellobiose to glucose, and plays an important role in the cellulase enzyme system with a synergic action with endoglucanase and cellobiohydrolase for cellulose degradation. Beta-glucosidase from T. harzianum type C-4 was purified to homogeneity through Sephacryl S-300, DEAE-Sephadex A-50, and Mono P column chromatographies. It was a single polypeptide with the molecular mass of 75,000 by SDS-PAGE. The enzyme was very active at pH 5.0 and 45 degrees C. No significant inhibition was observed in the presence of metal ions, thiol reagents, or EDTA. The enzyme was stable in the presence of 5% ox gall and digestive enzymes. p-Nitrophenyl-beta-D-cellobioside worked as a substrate for the enzyme as much as p-nitrophenyl-beta-glucopyranoside. Glucose and gluconolactone showed competitive inhibition with a Ki of 1 mM and 1.8 microM, respectively, while galactose, mannose, and xylose did not inhibit the enzyme significantly.

Cellulase↗

PubMed2001

Sorbicillinol, a key intermediate of bisorbicillinoid biosynthesis in Trichoderma sp. USF-2690.

In the course of our screening program for free radical scavengers from Trichoderma sp. USF-2690, we found an unidentified metabolite (1) that appeared by the method used for HPLC analysis. Metabolite 1 gradually decreased with the production of bisorbicillinoids and was easily missed during the general isolation procedure. The LC-ESI-MS (negative) analysis for 1 gave m/z 247 as the (M-1)- ion peak. The hydrolysis of synthetic 6-O-acetylsorbicillinol (+/- -2) by 0.05 M KOH and acetylation of product 1 in an aqueous solution indicated that the structure of 1 was (6S)-4-(2,4-hexadienoyl)-3,6-dihydroxy-2,6-dimethyl-2,4-cyclohexadien-1-one, designated sorbicillinol, a quinol that has been postulated to be important in bisorbicillinoid biosynthesis.

Bepridil↗

PubMed2002

Effects of amino acid alterations on the transglycosylation reaction of endoglucanase I from Trichoderma viride HK-75.

Endoglucanase I (EGI) from Trichoderma viride HK-75 catalyzes not only hydrolysis but also transglycosylation reactions of cellooligosaccharides. In order to characterize the important amino acid residues in transglycosylation of EGI, three Tyr, one Leu, and two Glu residues of EGI were replaced by Trp or Asp. The seven resulting EGI, except for L200W, had reduced activities toward carboxymethyl-cellulose compared to that of wild type EGI. The results from the mutations in the catalytic residues of E196 and E201 indicate that the space just around the catalytic residues is not directly related to the transglycosylation reactions of EGI. Analyses of the enzymes with mutations in the substrate-binding residues showed that Y146, Y170, and L200 of EGI are closely involved in the mode of transglycosylation and that several amino acid residues within the active site are involved in the transglycosylation reaction of EGI.

Amino Acid Substitution↗

PubMed2002

Transformation of Aspergillus sp. and Trichoderma reesei using the pyrithiamine resistance gene (ptrA) of Aspergillus oryzae.

A pyrithiamine (PT) resistance gene (ptrA) was cloned from a PT resistant mutant of Aspergillus oryzae and was useful as a dominant selectable marker for transformation of all A. oryzae wild type strain as well as A. nidulans. For further study, we examined whether or not ptrA could be used as the transformation marker in other species of filamentous fungi. Two types of plasmid, which contain ptrA as a selectable marker, were constructed, and the transformation experiments were done with them. One is an integrative plasmid, pPTRI, and another is the autonomously replicating plasmid pPTRII, which contains AMA1. PT-resistant transformants were obtained in the cases of A. kawachii, A. terreus, A. fumigatus, and Trichoderma reesei as hosts with pPTRI and pPTRII. Furthermore, a beta-glucuronidase (GUS) gene was introduced into A. kawachii and A. fumigatus using pPTRII. Almost all the transformants turned blue on GUS assay plates. These results indicate that ptrA can also be used for some other filamentous fungi besides A. oryzae and A. nidulans.

Aspergillus↗

PubMed2003

Purification and characterization of laminaran hydrolases from Trichoderma viride.

At least three extracellular laminaran hydrolases which hydrolyzed laminaran (beta-1,3:1,6-glucan) from Eisenia bicyclis were secreted in wheat bran solid medium by Trichoderma viride U-1. These three enzymes, lam AI, AII, and B, were purified to electrophoretic homogeneity. Their molecular masses were estimated to be 70.1, 70.4, and 45.0 kDa for lam AI, AII, and B, respectively, by SDS-PAGE. Whereas both lam AI and AII could hydrolyze laminarin from Laminaria digitata, lam AII showed higher activity against Laminaria laminarin rather than Eisenia laminaran. On the other hand, lam B preferentially hydrolyzed pustulan, a beta-1,6-glucan. Laminarioligosaccharide was hydrolyzed by lam AI and AII but not B, whereas gentiooligosaccharide was hydrolyzed by only lam B. It showed that lam AI and AII were specific for beta-1,3-linkages, but lam B was specific for beta-1,6-linkages. These results indicated that T. viride U-1 has a multiple glucanolytic enzyme system.

Fungal Proteins↗