Is-beta-alanine-specific opine dehydrogenase present?

通过测定各种海洋无脊椎动物的蛋白脱氢酶(OpDH)活性、等电聚焦聚丙烯酰胺凝胶电泳谱(IEF-PAG)和游离氨基酸水平，研究了海洋无脊椎动物Opin产生途径的分布。在几种动物中，观察到显著的β-丙氨酸脱氢酶(β-AIDH)活性。然而，没有在该物种中发现单独的β-AIDH活性的情况。在两种帽贝中，β-AIDH活性是主要的OpDH活性。然而，在许多其他物种中，b-ALDH活性被发现相当轻微的OpDH活性。在这些动物中，除了β-AIDH活性外，还观察到较高的丙氨酸脱氢酶(AIDH)和/或StdH活性。IEF-PAG分析表明，β-AIDH活性和AIDH活性的带型几乎相同，表明后者是一种显示β-AIDH活性的广谱特异性OpDH。用…提纯OpDHs更多的和特征是帽贝Cellana grata和腹足类Fusitriton oregonensis。除了TADH活性和弱的乳酸脱氢酶活性外，大口鱼的肌肉组织还具有β-AIDH活性。分离纯化了两种不同类型的OpDHs，分别为TADH和具有β-AIDH活性的OpDHs。从对氨基酸和Opine的特异性来看，显示β-AIDH活性的OpDH是一个真正的对β-丙氨酸具有严格底物专一性的β-AIDH。虽然两种酶的催化性质基本相似，但在氨基酸底物专一性和K_m值方面有所不同。β-AIDH和TADH在分子性质上有很大的相似性。这些结果清楚地表明，帽状肌中存在β-丙氨酸特异的OpDH，即真正的β-AIDH。另一方面，在奥勒冈对虾的肌肉中观察到了AIDH、STDH、β-AIDH和TADH的活性。共分离出四种酶。研究表明，Oregonsis OpDHs是一种广谱专一性的酶。OpDHs的催化性能表明，β-AIDH活性没有生理意义。因此，可以得出结论：真的存在β-AIDH，但在无脊椎动物中检测到的所有β-AIDH活性也不表明动物中存在β-丙氨酸的形成途径。较少

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