Tissue-specific alanopine dehydrogenase and strombine dehydrogenase from the sea mouse,Aphrodite aculeata (polychaeta)

✍ Scribed by Storey, Kenneth B.

• Book ID: 102894722
• Publisher: John Wiley and Sons
• Year: 1983
• Tongue: English
• Weight: 795 KB
• Volume: 225
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1402250304

✦ Synopsis

Each tissue of the sea mouse, Aphrodite aculeata, contains a single cytoplasmic dehydrogenase acting at the pyruvate branchpoint: Alanopine dehydrogenase (ADH) occurs in longitudinal muscle, nerve, and elytra, and strombine dehydrogenase (SDH) characterizes pharynx and intestine. Lactate and octopine dehydrogenases were not detected in any tissue. ADH from muscle and SDH from pharynx were partially purified. The two enzymes had the same molecular weight, 44,000 k 4,000 but differed in isolelectric point.

Although similar in keto acid specificity, the enzymes differed strongly in amino acid specificity. Pharynx SDH showed a very high specificity for glycine, all other alternative amino acids showing very high apparent K, s andlor low Vrnaxs. Muscle ADH, however, displayed high velocities and relatively low apparent K, s with L-alanine, L-serine, L-threonine, and L-cysteine. Amino