Purification, characterization, and cDNA cloning of opine dehydrogenases from the polychaete rockworm Marphysa sanguinea.

Alanopine dehydrogenase (AlDH) and three isoforms of strombine/alanopine dehydrogenase (St/AlDH) were purified from muscle tissue of the polychaete rockworm Marphysa sanguinea. The four enzymes, which can be distinguished by the isoelectric point, are monomeric 42 kDa proteins, possess similar pH-activity profiles, and display specificity for pyruvate and NAD(H). The three isoforms of St/AlDH show equivalent Km and Vmax for glycine and L-alanine and for D-strombine and meso-alanopine.

Tauropine dehydrogenase from the marine sponge Halichondria japonica is a homolog of ornithine cyclodeaminase/mu-crystallin.

The partial amino acid sequence including the N- and C-terminal portions of tauropine dehydrogenase (EC 1.5.1.

The amino acid sequence of tauropine dehydrogenase from the polychaete Arabella iricolor.

The amino acid sequence of tauropine dehydrogenase (EC 1.5.1.

Presence of free D-amino acids in microalgae.

Several species of microalgae (phytoplankton), 4 species of freshwater algae and 4 species of marine diatoms, were cultured germ-free in the laboratory. The presence of free D-amino acids was verified in these species by a reversed-phase HPLC analysis. D-Aspartate was detected in all the microalgae examined, but D-alanine was only present in the marine diatoms.