Isolation and Preliminary Characterization of Developmental Mutants from Microsporum gypseum

1974

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Inorganic phosphate was found to decrease the caseinolytic and ethyl-esterase activities of the Microsporum gypseum germination protease. The germination protease possessed exokeratinase (beta-keratinase) activity immediately after release from the fungal spore. After phosphate treatment of the enzyme, the germination protease also possessed endo-keratinase (alpha-keratinase) activity. Phosphate altered the protease's pH optimum from 9.0 to 7.0 and decreased the molecular weight from 33,000 to 16,000. These values were identical to those found for the keratinase. Alphaand beta-keratinase activities were stimulated in excess of 200-fold by disulfide reducing agents. Natural and suspected keratin degradation products also enhanced keratinase activity. Cell fractionation and in vitro conversion of the alkaline germination protease into a functional keratinase suggested that the subunits comprising the germination protease and the keratinase were of a common origin.

Section: Discussionmentioning

confidence: 95%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Phosphate-Mediated Alteration of theMicrosporum gypseumGermination Protease Specificity for Substrate: Enhanced Keratinase Activity

1974

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“…The waterinsoluble glycoprotein from spores was notably low in basic amino acids and had an increased content of acidic amino acids. The water-insoluble glycoprotein also contained considerable quantities of aromatic amino acids, which could make this fraction susceptible to alkaline germination protease attack in vivo (12). The amino acid analysis of the glycoprotein fractions revealed that the ethylenediaminesoluble, water-soluble glycoproteins from both strain R87 spores and R87P1 vegetative hyphae were of similar composition, suggesting that, if the water-soluble glycoprotein of the spores was derived from its mycelial counterpart, it had undergone very little compositional transformation during sporulation.…”

Section: Discussionmentioning

confidence: 99%

Changes inMicrosporum gypseumMycelial Wall and Spore Coat Glycoproteins During Sporulation and Spore Germination

1974

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Ethylenediamine-soluble glycoproteins were extracted from isolated Microsporum gypseum hyphal walls during sporulation and from spore coats before and after germination. This study was carried out to identify a sporulationspecific cell wall protein that possibly served as a substrate for the alkaline protease which initiated the macroconidial germination of this fungus. Analyses revealed that water-insoluble glycoprotein accounted for 10% of the ungerminated spore coat but only for 4 to 5% of the mycelial wall dry weight. This fraction was modified in its amino acid composition during sporulation, and it decreased in protein content during spore germination. Water-soluble glycoprotein, which accounted for approximately 3 to 3.5% of either the spore coat or mycelial wall dry weight, was of similar amino acid composition from both sources and did not decrease in protein content upon spore germination. The water-insoluble glycoprotein was found to be rich in leucine, aspartic acid, glycine, glutamic acid, and phenylalanine residues. The water-soluble glycoprotein was rich in proline, threonine, glycine, serine, glutamnic acid, and alanine.Spores were purified and germinated as described previously (10).

“…A strain of M. gypseum (Bodin; Guiart and Grigorakis, 1928; designated strain R87) originally obtained from F. Blank, Temple University, Philadelphia, Pa., was used in these investigations. This strain was previously designated SP+Pig+ (8). An asporogenous pleomorphic strain of R87, previously designated SP2 Pig- (8), also was used in these studies.…”

Section: Methodsmentioning

confidence: 99%

Isolation and Characterization of Microsporum gypseum Lysosomes: Role of Lysosomes in Macroconidia Germination

1972

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Three types of lysosomes containing either acid protease, alkaline protease, or phosphodiesterase were isolated from a Microsporum gypseum macroconidial homogenate on Ficoll gradients. The acid protease was contained in an assimilative lysosome since its activity was affected by the complexity of the exogenous nitrogen source. Ultracentrifugation and electron microscopy revealed that the alkaline protease-containing vesicles were associated with the spore coat material prior to macroconidial germination. During macroconidial germination, zones of spore coat hydrolysis were seen surrounding these vesicles. Other larger vesicles, believed to contain the phosphodiesterase, were also observed in the spore coat during macroconidial germination.