Sulphitolysis in keratinolysis. Biochemical proof

Ruffin, P; Andrieu, S; Biserte, G; Biguet, J.

doi:10.1080/00362177685190251

Cited by 36 publications

(12 citation statements)

References 11 publications

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“…The highest sulfate release and protease activity occurring at the same time, noted in the present study, suggests that these processes may occur in parallel. This suggestion is supported by the results obtained by Ruffin et al (1976) conducted in cultures of keratinolytic fungi. They show that sulfitolysis occurs in parallel with proteolysis of native keratin.…”

Section: Discussionsupporting

confidence: 81%

Biodegradation of feather waste keratin by a keratinolytic soil fungus of the genus Chrysosporium and statistical optimization of feather mass loss

Bohacz

2016

World J Microbiol Biotechnol

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This paper assesses the ability of strains of Aphanoascus fulvescens and Chrysosporium articulatum isolated from soil (phaesol) to degrade native feather keratin. Strains were identified based on phenotypic traits and nucleotide sequencing. Response Surface Methodology was used to optimize cultivation conditions exhibiting the highest keratinolytic activity. The experiments were based on Box-Behnken designs for the loss of substrate mass (chicken feathers). While substrate mass loss is an “economic coefficient” that reliably indicates feather keratin degradation, it has not been studied before. Stationary liquid cultures of five selected strains were conducted in laboratory conditions at 28 °C using poultry feathers (1 g) as the sole source of carbon, nitrogen and energy. Enzymatic activities, keratin mineralization products and substrate mass loss were determined periodically. The mineralization of keratin proteins by strains yielded a high number of ammonium ions alkalinizing the medium. Increased ammonium ions inhibited the activity of caseinian protease and keratinase. A decrease in the concentration of these ions induced proteolytic enzymes, chiefly the activity of keratinase, at the end of fungal cultivation. Keratinase activity was related to protein- and peptide release and that of caseinian protease to sulfate ions. The highest loss of substrate mass in comparison to the reference strain CBS104.62 (35.4%) was recorded for Aphanoascus fulvescens B21/4-5 (65.9%). Based on a Box-Behnken design, the maximum loss of substrate mass for the Aphanoascus fulvescens strain (71.08%) can be achieved at pH 7.58 and temperature 28.7 °C.

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Section: Discussionsupporting

confidence: 81%

Biodegradation of feather waste keratin by a keratinolytic soil fungus of the genus Chrysosporium and statistical optimization of feather mass loss

Bohacz

2016

World J Microbiol Biotechnol

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“…The presence of sulphocysteine has been confirmed by histochemical methods in human hair attacked by Microsporum gypseum (Kunert, 1972b). This compound was found in the free form and in oligopeptides of~700-2500 Da which were products of keratinolysis (Kunert, 1976;Ruffin et al, 1976). As highly specialized fungi, the dermatophytes are able to metabolize free cystine added to a nutrient broth, and excrete excess sulphur as sulphate and sulphite.…”

Section: Introductionmentioning

confidence: 88%

Sulphite efflux pumps in Aspergillus fumigatus and dermatophytes

Léchenne

Reichard²,

Zaugg

et al. 2007

Microbiology

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Dermatophytes and other filamentous fungi excrete sulphite as a reducing agent during keratin degradation. In the presence of sulphite, cystine in keratin is directly cleaved to cysteine and Ssulphocysteine, and thereby, reduced proteins become accessible to hydrolysis by a variety of secreted endo-and exoproteases. A gene encoding a sulphite transporter in Aspergillus fumigatus (AfuSSU1), and orthologues in the dermatophytes Trichophyton rubrum and Arthroderma benhamiae (TruSSU1 and AbeSSU1, respectively), were identified by functional expression in Saccharomyces cerevisiae. Like the S. cerevisiae sulphite efflux pump Ssu1p, AfuSsu1p, TruSsu1p and AbeSsu1p belong to the tellurite-resistance/dicarboxylate transporter (TDT) family which includes the Escherichia coli tellurite transporter TehAp and the Schizosaccharomyces pombe malate transporter Mae1p. Seven genes in the A. fumigatus genome encode transporters of the TDT family. However, gene disruption of AfuSSU1 and of the two more closely related paralogues revealed that only AfuSSU1 encodes a sulphite efflux pump. TruSsulp and AbeSsulp are believed to be the first members of the TDT family identified in dermatophytes. The relatively high expression of TruSSU1 and AbeSSU1 in dermatophytes compared to that of AfuSSU1 in A. fumigatus likely reflects a property of dermatophytes which renders these fungi pathogenic. Sulphite transporters could be a new target for antifungal drugs in dermatology, since proteolytic digestion of hard keratin would not be possible without prior reduction of disulphide bridges.

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“…Although in vivo T. rubrum tends not to attack hair, the key reaction in the decomposition of keratin is probably suphitolysis [11,15] and it has been suggested that proteolytic digestion and sulphitolysis are simultaneous complementary phenomena leading to the transformation of keratin into soluble material of nutritive value to the fungus.…”

mentioning

confidence: 99%

Enzymic activities ofTrichophyton rubrumand the chemotaxis of polymorphonuclear leucocytes

Davies¹,

Zaini²

1984

Med Mycol

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The enzymic activity of Trichophyton rubrum has been investigated in relation to the plasmadependent chemotaxis of polymorphonuclear leucocytes (PMNs). In Boyden-type experiments use of a cytoplasmic extract of T. rubrum (CETr) produces neutrophil ehemotactic factor (NCF) from plasma. CETr was shown to have activity for eight enzymes: heat treatment of CETr led to a partial loss of activity for seven enzymes and a significant reduction in the number of PMNs migrating. Addition of CETr to plasma and incubation for 18 h at 37"C before use led to complete loss of chemotactic activity. The similar incubation of plasma with trypsin led to a complete loss of chemotactic activity. CETr has greater activity than trypsin in the production of NCF from plasma. The results are discussed in relation to reports on the importance of serine esterases in PMN chemotaxis. The failure of PMNs to migrate into keratinized tissue infected with T. rubrum is noted and it is suggested that the high enzymic activities necessary for the colonization of keratinized tissue effect a breakdown of NCF.In experiments with a Boyden-type chamber a cytoplasmic extract of Trichophyton rubrum (CETr) induced a plasma-dependent chemotaxis of polymorphonuclear leucocytes (PMNs) [8]. Although no chemotaxis occured in the absence of plasma, chemotaxis was induced with use of CETr and plasma in which the complement had been inactivated by heat and it was concluded that CETr mimics the activity of the complement system in the production of neutrophil chemotactic factor (NCF). NCF production by CETr activation of complement also occured and was primarily through the alternative (antibody independent) pathway [8].Trypsin-like enzymes activate complement by both the classical and alternative pathways [14] and Wilkinson [24] has reviewed the studies of Becker and his associates [3,20,21,2] which show the importance of serine esterases in chemotaxis. Among the well known enzymes which may be classified as serine esterases, alkaline phosphate, C1 esterase, trypsin, chymotrypsin, elastase, thrombin, cholinesterase, acetylcholinesterase and aliesterase have been listed [4,24]. The hydrolysis of esters and peptides by extracts of T. rubrum and use of synthetic substrates with enzymes from T. rubrum has shown the specificities of trypsin and chymotrypsin [7].

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Sulphitolysis in keratinolysis. Biochemical proof

Cited by 36 publications

References 11 publications

Biodegradation of feather waste keratin by a keratinolytic soil fungus of the genus Chrysosporium and statistical optimization of feather mass loss

Biodegradation of feather waste keratin by a keratinolytic soil fungus of the genus Chrysosporium and statistical optimization of feather mass loss

Sulphite efflux pumps in Aspergillus fumigatus and dermatophytes

Enzymic activities ofTrichophyton rubrumand the chemotaxis of polymorphonuclear leucocytes

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