Rat epidermal cathepsin L-like proteinase: purification and some hydrolytic properties toward filaggrin and synthetic substrates.
We have purified cathepsin L-like proteinase from rat epidermis, determined its NH2-terminal amino acid sequence, and investigated its proteolytic activities on an intermediate filament-associated protein filaggrin and several synthetic substrates. The amino acid sequence of its NH2-terminus was determined to be Val-Pro-Asn-Ser-Leu-Asp-Trp-Arg-Glu-Lys-Gly-Tyr-Val-Thr-Pro-, which differed from that of rat cathepsin L and was not found in the amino acid sequence data bank. The enzyme consisted of a single-chain form with M(r) 30,000. Its hydrolytic properties toward synthetic substrates were similar to those of cathepsin L in other tissues. The enzyme effectively proteolyzed rat epidermal filaggrin into small fragments at pH 4.0-6.0 and was inhibited by a specific cysteine proteinase inhibitor, N-[N-(L-3-trans-carboxyoxirane-2-carbonyl)L-leucyl]-agmatin. However, cathepsins D and E from rat epidermis did not hydrolyze filaggrin. This study demonstrated that filaggrin was susceptible to degradation by rat epidermal cathepsin L-like proteinase, suggesting that this proteolytic activity may have relevance to skin differentiation, in which acid proteases are thought to participate.
Department of Dermatology, National Defense Medical College, Saitama.
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A
Kawada
K
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Hara
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M
Hiruma
H
H
Noguchi
A
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Ishibashi
D000595:Amino Acid Sequence; D000818:Animals; D056668:Cathepsin L; D002403:Cathepsins / Q000737:chemistry / Q000378:metabolism*; D002852:Chromatography, Ion Exchange; D003546:Cysteine Endopeptidases / Q000302:isolation & purification* / Q000378:metabolism; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D010450:Endopeptidases; D004817:Epidermis / Q000201:enzymology*; D000091344:Filaggrin Proteins; D006801:Humans; D006868:Hydrolysis; D007381:Intermediate Filament Proteins / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D051381:Rats; D017207:Rats, Sprague-Dawley; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D013696:Temperature
D015853:Cysteine Proteinase Inhibitors; C000717249:FLG protein, human; D000091344:Filaggrin Proteins; D007381:Intermediate Filament Proteins; D002403:Cathepsins; D010450:Endopeptidases; D003546:Cysteine Endopeptidases; C534281:CTSL protein, human; D056668:Cathepsin L; C534280:Ctsl protein, rat