PROTEIN DERIVATIVE AND PRODUCTION THEREOF

摘要

PURPOSE:To obtain a protein derivative having an extremely prolonged life in blood in comparison with protein alone while nearly maintaining physiological activity of protein as it is by reacting a protein with a specific long-chain carboxylic acid imide ester in an aqueous solution at a specific pH. CONSTITUTION:A protein (e.g. superoxide dismutase) is reacted with a long-chain carboxylic acid imide ester [e.g. N-(13-carboxytridecanoyloxy)succinic acid imide] shown by formula I [W is bifunctional long-chain hydrocarbon which may be interrupted with one or more of O, S and NR (R is lower alkyl) in an aqueous solution at pH6-10 to give the objective protein derivative shown by the formula [protein] [Z]. ([protein] is protein containing X residue obtained by eliminating one H from amino group instead of amino group; [Z] is group shown by formula II; X is average value of number of amide bonds between [Z] and [protein] and is 1-8 number).