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1. Adenylate kinase (ATP: AMP phosphotransferase) has been purified 490-fold from porcine muscle with a final yield of 60 mg/kg muscle. 2. The amino-acid composition is Asp11 Asn2, Thr14, Ser11, Glu19,, Gln6, Pro6, Gly19>, Ala6, Cyst2, Val17, Met6, Ile9, Leu18, Tyr7, Phe5, Lys21, His2, Arrg11. 3. The protein molecules a single polypeptide chain of 194 amino-acid residues with an acetylmethionine at the N-terminus and a lysine residue at the C-terminus. 4. Cyanogen bromide cleavage of carboxymethylated adenylate kinase yielded six fragments which were further degraded by using trypsin, chymotrypsin, thermolysin, subtilisin or α-protease. Sequence data on the resulting peptides are summarized in the present report, full details are given in a supplementary paper which has been deposited at CNRS from where copies can be obtained. 5. The primary structure of porcine adenylate kinase was given. [ABSTRACT FROM AUTHOR]

The purification of two different forms of prephospholipase A2 from porcine pancreas is described in the accompanying paper. One of these has an activation pepticle with the sequence

The object of this paper is to analyse the effects of the coenzymes NAD(P)+ and NAD(P)H, and the effectors ADP and GTP, on the polyhexameric structure of pig-liver dehydrogenase. The linear polymerisation model proposed by Eisenberg for the native quaternary structure of this protein is valid with any effector; the observed variations of the degree of polymerization are explained by the modification of the apparent association constant of the hexamers. The appendices I and II define the free and associated areas and give, the theoretical foundations of the variation of the association constant of hexamers in terms of the binding of the ligands to the protemers. The increase in the degree of polymerization of the glutamate dehydrogenase with the binding of NAD(P)H is explained by a higher affinity of the coenzymes for the protomers which have an associated area compared to the protomers which have a free area. No variation is observed with NAD(P)+, ADP, or GTP alone. The formation of the protein · GTP · NAD(P)H ternary complex leads to a complete depolymerization when the two ligands are in saturating concentrations. The systematic study of the variations of polymerization in terms of increasing concentration of NAD(P)H at constant concentration of GTP, or in terms of increasing concentration of GTP at constant concentration of NAD(P)H shows that the interaction between the two opposite protomers of two consecutive hexamers is responsible for the sigmoidal shape of the depolymerization curves. The reversibility of this effect by ADP is assigned to a competition between the binding of ADP and the binding of GTP. [ABSTRACT FROM AUTHOR]