Is-beta-alanine-specific opine dehydrogenase present?

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Distribution of opin production pathway was examined for a wide variety of marine invertebrates by a combination of activities of opine dehydrogenases (OpDH), band patterns on isoelectric focusing in polyacrylamide gel electrophoresis (IEF-PAG), and levels of free amino acids. In several animals, significant beta-alanopine dehydrogenase (beta-AIDH) activity was observed. However, there was no case that beta-AIDH activity alone was found in the species. beta-AIDH activity was found as a dominant OpDH activity in the two species of limpets. However, in many other species, b-ALDH activity was found rather minor OpDH activity. In those animals, higher activities of alanopine dehydrogenase (AIDH) and/or strombine dehydrogenase (StDH) in addition to beta-AIDH activity was observed. IEF-PAG analysis showed that band patterns for beta-AIDH activity and AIDH activity were nearly identical, suggesting that later enzyme was a broadly specific OpDH showing beta-AIDH activity. OpDHs were purified a … More nd characterized from the limpet Cellana grata and the gastropod Fusitriton oregonensis. The muscular tissues of the lipet C.geata exhibited beta-AIDH activity in addition to TaDH activity and weak lactate dehydrogenase activity. OpDHs were purified, and two different types of OpDH,TaDH and OpDH showing beta-AIDH activity, were isolated. From the specificity for amino acid and opine, OpDH showing beta-AIDH activity was concluded to be a true beta-AIDH showing strict substrate specificity for beta-alanine. While the catalytic properties of the two enzymes were essentially similar, they were distinct from each other with respect to the amino acid substrate specificity and the K_m values. Great similarities were found between beta-AIDH and TaDH with respect to molecular properties. These results clearly showed that beta-alanine specific OpDH,true beta-AIDH,was present in the limpet muscle. On the other hand, activities of AIDH,StDH,beta-AIDH,and TaDH were observed in the muscle of F.oregonensis. Four enzymes were isolated. The characterization study showed that F.oregonensis OpDHs were broadlyspecific enzymes. The catalytic properties of OpDHs showed that beta-AIDH activity had no physiological mean. Thus it was concluded that true beta-AIDH was present, but it was also true that all of beta-AIDH activity detected in invertebrate did not indicated the presence of beta-alanopine formation pathway in the animal. Less