The importance of SH-groups for enzyme activity: VIII. The amino acid sequence around the essential cysteine residue of lactate dehydrogenase from pig heart, pig and chicken muscle
Mella, Klaus; Folsche, E.T.J.; Torff, H.Joachim; Pfleiderer, G.
Hoppe Seylers Z Physiol Chem 349(7): 891-895
The amino acid sequences of the essential cysteine peptides from pig muscle lactate dehydrogenase and chicken muscle lactate dehydrogenase are given and shown to be identical with the sequence of the peptide from pig heart lactate dehydrogenase. From these results the initial sequences of the essential cysteine peptides of lactate dehydrogenases are presented. The kinetics of hydrolysis in the digestion of the essential cysteine peptide from pig heart lactate dehydrogenase by aminopeptidase M and leucine aminopeptidase were compared. As a result it was found that aminopeptidase M hydrolyzes peptide-bonds of glycine and carboxy-methylcysteine at a normal rate, while these bonds are hydrolyzed with difficulty by leucine aminopeptidase.