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R Messner

Publications and source records attributed to R Messner.

14 recordsLinked to original sources
PubMed1992

The two major xylanases from Trichoderma reesei: characterization of both enzymes and genes.

As a first step to exploit the potential of Trichoderma reesei to produce hemicellulases, we have purified two endo-beta-1,4-xylanases (1,4-beta-D-xylan xylanohydrolase, EC 3.2.1.8) and cloned their genes. The enzymes were isolated from culture filtrates of T. reesei C30 grown on xylan as a carbon source, using two steps of cation exchange chromatography. They exhibited molecular weights of 19 (XYN I) and 21 (XYN II) kD, and isoelectric points of 5.2 and 9.0, respectively. These enzymes differed in their pH optimum for activity and affinity for xylan, and accounted for more than 90% of the total xylanolytic activity of the fungus. The purified enzymes were subjected to N-terminal sequence analysis, and after cleavage with trypsin and endoproteinase Glu-C the resulting peptides were sequenced. Oligonucleotides based on these sequences were used to clone gene fragments via PCR, and these were used as probes to isolate full-length copies of xyn1 and xyn2 from a lambda gene bank of T. reesei. The products of xyn1 and xyn2 share considerable homology, but the enzyme encoded by xyn2 appears to more closely resemble several other bacterial and fungal xylanases than does that of xyn1.

Amino Acid Sequence↗
PubMed1991

Cellobiohydrolase II is the main conidial-bound cellulase in Trichoderma reesei and other Trichoderma strains.

Monoclonal antibodies have been used to determine the presence of cellobiohydrolases I and II (CBH I and II), and endoglucanase I (EG I) on the surface of conidia from Trichoderma reesei QM 9414 and RUT C-30, and 8 other Trichoderma species. For this purpose, proteins were released from the conidial surface by treatment with a non-ionic detergent (Triton X-100 and beta-octylglucoside), followed by SDS-PAGE/Western blotting and immunostaining. Both CBH I and II were clearly present, but - unlike in extracellular culture fluids from Trichoderma - CBH II was the predominant cellulase. In T. reesei EG I could not be detected. The higher producer strain T. reesei RUT C-30 exhibited a higher conidial level of CBH II than T. reesei QM 9414. In order to assess the importance of the conidial CBH II level for cellulase induction by cellulose, multiple copies of the chb2 gene were introduced into the T. reesei genome by cotransformation using PyrG as a marker. Stable multicopy transformants secreted the 2- to 4-fold level of CBH II into the culture medium when grown on lactose as a carbon source, but their CBH I secretion was unaltered. Upon growth on cellulose, both CBH I and CBH II secretion was enhanced. Those strain showing highest cellulase activity on cellulose also appeared to contain the highest level of conidial bound CBH II. CBH II was also the predominant conidial cellulase in various other Trichoderma sp. However, roughly the same amount of conidial bound CBH II was detected in all strains, although their cellulase production differed considerably.

Antibodies, Monoclonal↗
PubMed1990

The homeless.

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Health Services Needs and Demand↗
PubMed1989

Monoclonal antibodies against different domains of cellobiohydrolase I and II from Trichoderma reesei.

Monoclonal antibodies have been produced against two functionally different domains present in two cellobiohydrolases from Trichoderma reesei (CBH I and CBH II). Four groups of antibodies were obtained, which specifically recognized (Western blotting, ELISA) (a) the core protein within CBH I, (b) the core protein within CBH II, (c) the BA region of CBH I, and (d) the ABB' region of CBH II. No cross-reactivities within these four groups were observed. The antibodies reacted also specifically with proteins of similar size to CBH I and CBH II (SDS-PAGE) from other Trichoderma strains (Western blotting), whereas no reaction was observed with cellulases from other fungal sources. Analysis of culture filtrates of T. reesei QM 9414 harvested at various times of growth on cellulose under buffered conditions (pH 5-6) indicated the presence of only single bands of CBH I and CBH II, even after prolonged cultivation (160 h). Cultivation on cellulose in unbuffered media, however, showed the appearance (Western blotting) of additional lower molecular weight proteins, which reacted with the monoclonal antibodies directed against the cores of CBH I and II, but not with those recognizing the respective BA and ABB' regions. The appearance of these lower molecular weight bands was most pronounced in unbuffered media, supplemented with a 3-fold (w/w) amount of organic nitrogen (peptone). Analysis of some commercial cellulase preparations from T. harzianum revealed the same pattern of lower molecular weight proteins, in contrast to samples from other fungal cellulases. Those samples or preparations, showing a multiple pattern of CBH I and CBH II, exhibited higher activities of an acid proteinase. These results imply that the use of unbuffered, high nitrogen-supplemented culture conditions for production of cellulases may lead to considerable proteolytic modification of the secreted cellobiohydrolases.

Antibodies, Monoclonal↗
PubMed1988

Differential regulation of synthesis of multiple forms of specific endoglucanases by Trichoderma reesei QM9414.

A method consisting of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and subsequent detection of endoglucanases by blotting with a polyclonal antibody against endoglucanase I was used to investigate the effect of induction and carbon catabolite derepression on the synthesis of multiple forms of endoglucanase I by Trichoderma reesei. Five forms appeared upon growth on cellulose, whereas four and only two appeared upon growth on lactose (carbon catabolite derepression) and induction by sophorose in a resting cell system, respectively. All endoglucanases detected resembled endoglucanase I in their specificity, since they exhibited no activity toward xylan or paranitrophenyl-beta-D-lactobioside. A small (25-kilodalton) endoglucanase only appeared during growth on cellulose. None of the multiple forms arose by postsecretional modification. The results indicate that sophorose may not be the only compound mediating cellulose induction of the specific endoglucanases in T. reesei.

Cellulase↗
PubMed1986

Neurofibromatosis: relinquishing the masks; a quest for quality of life.

Neurofibromatosis (NF) or von Recklinghausen's disease is mankind's most common neurologic genetic disorder, occurring in one of every 3000 live births. While many individuals with NF suffer disfiguring, disabling, or life-threatening complications, NF is extremely variable in its symptoms, intensity, and progression. For many of its victims, NF is a pseudonym for uncertainty and physical and psychosocial havoc. John Merrick, 'The Elephant Man', endured one of the most severe cases of NF ever recorded. Merrick's rejection by post-Dickensian England forced him to become a sideshow circus attraction just to survive. The essence of nursing intervention with NF patients and their families engaged in the quest for quality of life is to restore them to optimal physical and psychosocial functioning, and, ideally, to help them utilize the experience for growth. Many individuals respond to the frustration of NF and society's reactions to the disorder by the wearing of psychological masks. Likewise, nurses may wear emotional masks as a defence against their own discomfort and fears concerning the disorders. Comprehensive nursing management of NF is realized only as nurses and patients relinquish their respective masks. This article examines the nurse's role in genetic disorders with special considerations presented by NF. Adaptation to NF involves coping with NF and its accompanying sequelae and coping with life as it is affected by NF. The concepts of 'chromosomal coping', 'genetophobia', 'genetic guilt, and 'genetic overload syndrome' are presented and analyzed utilizing the theoretical nursing frameworks of Imogene King and Sister Callista Roy.

Adaptation, Psychological↗
PubMed1978

Septic bursitis.

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Adult↗
PubMedDate not supplied

Patellar whiskers and acute calcific quadriceps tendinitis in a general hospital population.

Described is a case of acute calcific quadriceps tendinitis which presented as monoarticular arthritis. A survey of general hospital patients revealed a 7% incidence of calcification of the superior patellar tendon. The most common concurrent abnormality was degenerative joint disease (94%); concomitant chondrocalcinosis was not seen. The "patellar whisker" is a relatively common x-ray finding that may be the clue to an uncommon cause of acute arthritis.

Adolescent↗