Abstract: A fusion protein comprising a carrier and a desired peptide or protein linked to the carrier via an enzymatically excisable dipeptide, such as Lys-Arg, is produced in a host microorganism and then the desired peptide or protein is recovered by treating the fusion protein at least with a protease specifically recognizing the dipeptide and specifically hydrolyzing the peptide bond of the dipeptide. The fusion protein includes tandem-form fusion proteins in which desired peptide or protein molecules are linked together repeatedly. According to the cleavage site in the dipeptide, the protease may be used in combination with an aminopeptidase specifically releasing a basic amino acid from the N-terminal side of the dipeptide and/or a carboxypeptidase specifically releasing a basic amino acid from the C-terminal side of the dipeptide.

Abstract: There is disclosed a protease having the following enzymatic properties in view of:(a) function and substrate specificity,(b) optimum pH,(f) activation, and(g) inhibition;(a) the protease can hydrolyze, in particular, a peptide bond on the C-terminal side of Y of a peptide X--Y--, in which X is Arg, Lys or Pro optionally having a peptide bond on the N-terminal side, Y is Arg and -- indicates a peptide bond;(b) the protease has an optimum pH of about 7.0 in Tris hydrochloride buffer;(f) the protease is activated with calcium chloride or a surfactant; and(g) the protease is inhibited with p-amidinophenylmethanesulfonyl fluoride, p-chloromercuribenzoic acid, a metal chelater, tetraacetic acid or a heavy metal.

Abstract: Disclosed are an optically active, ethylenically unsaturated monomer represented by the following structural formula: ##STR1## wherein: A stands for S, SO or SO.sub.2 ; X and Y each stand for a hydrogen atom or a substituent selected from the group consisting of alkyl groups and acyl groups; Z stands for a substituent selected from the group consisting of alkoxy, alkylamino, hydroxyl and silyloxy groups; and X and Y can be bonded together to form a ring with the nitrogen atom to which they are bonded or X and Y can be a single group bonded to said nitrogen atom through a double bond, with the proviso that at least one of X and Z is an alkenyl equivalent to said group, and polymers of this monomer. One typical instance of the monomer is benzyl 6-acrylaminopenicillanate.