III. THE RIBONUCLEASES OF HUMAN EPIDERMIS
MELBYE, SUSANNE W. ; BRANT, BARBARA A. ; FREEDBERG, IRWIN M.
Oxford, UK : Blackwell Publishing Ltd
Published 1977
Oxford, UK : Blackwell Publishing Ltd
Published 1977
| ISSN: |
1365-2133
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| Source: |
Blackwell Publishing Journal Backfiles 1879-2005
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| Topics: |
Medicine
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| Notes: |
Sodium acetate and sulphuric acid extracts of human epidermis can each be separated by chromatographic techniques into three or more fractions with ribonuclease activity. Eight of these fractions were compared with respect to molecular weight, pH activity profile, polyribonucleotide hydrolysis, and activity in the presence of low levels of spermidine. Sodium acetate and sulphuric acid extracts were also prepared from callus and from psoriatic lesions and compared with extracts from normal epidermis for their response to exogenous spermidine.All eight human epidermal ribonuclease fractions studied had an apparent molecular weight of 15,000 daltons. Seven of the ribonuclease fractions were optimally active at alkaline pHs (pH 7.3–7.6 in sodium phosphate and pH 81.in Tris-HCl) while the eighth ribonuclease was most active at pH 5.6 in a citrate-phosphate buffer. All enzymes hydrolyzed polycytidylic acid and five also hydrolyzed polyuridylic add. None hydrolyzed polyadenylic acid. Seven of the eight ribonucleases studied exhibited greater activity in the presence of added spermidine. The extracts from psoriatic scales showed markedly elevated ribonuclease levels which could not be raised further by the addition of spermidine.
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| Type of Medium: |
Electronic Resource
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| URL: |