Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0847097 (acidity)
 15,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

L-Asparaginase from Escherichia coli was coupled with two types of comb-shaped copolymer of poly-(ethylene glycol) derivative and maleic anhydride (activated PM), having molecular weights of 13,000 and 100,000 (activated PM13 and PM100, respectively) with multivalent reaction sites. After single intravenous injections of PM100-asparaginase and nonmodified asparaginase into rats, the enzymic activity of PM100-asparaginase in serum was well retained for at least 11 days, and the serum L-asparagine concentration remained undetectable for 27 days. The half-lives of PM100-asparaginase and nonmodified asparaginase were 50 and 1.5 h, respectively. Stabilization of L-asparaginase toward heat, urea, and acidity was caused by modifying the enzyme with activated PM13 and PM100. Especially, PM100-asparaginase retained high enzymic activity toward heat and urea, compared with PM13-asparaginase. It was suggested that these modifiers with a comb-shaped form and with multivalent reactive sites cover the whole surface of the asparaginase molecule and stabilize its conformation possibly through multiple covalent bindings and through various noncovalent interactions.
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PMID:Stabilization of L-asparaginase modified with comb-shaped poly(ethylene glycol) derivatives, in vivo and in vitro. 794 93