|
Author:
Date:
2015-10-20
[Abstract] Prominent accumulation of D-leucine, D-allo-isoleucine and D-valine was observed in the culture medium of the heterofermentative bacterial species, Lactobacillus otakiensis (L. otakiensis) JCM 15040. The racemase enzyme that resulted in this accumulation, isoleucine 2-epimerase, was purified from the bacterial cells. This is the first reported observation of such production of D-branched chain amino acids in lactic acid bacteria, and the first example of a racemase with isoleucine 2-epimerase activity in any organisms. In the described protocol, we introduce methods for purification of this protein from L. otakiensis JCM 15040. Because no specific ligand that has high affinity for this enzyme has been identified, the purification was performed using ...
[摘要] 在异质发酵细菌物种，例如otakiensis的乳酸杆菌（Lactobacillus otakiensis）的培养基中观察到D-亮氨酸，D-异亮氨酸 - 异亮氨酸和D-缬氨酸的显着积累。 otakiensis）JCM 15040.从细菌细胞中纯化导致这种积累的消旋酶，异亮氨酸2-差向异构酶。这是首次报道的在乳酸菌中这种D-支链氨基酸的产生的观察结果，以及在任何生物体中具有异亮氨酸2-差向异构酶活性的消旋酶的第一个实例。在所述的方案中，我们介绍从L中纯化该蛋白质的方法。因为没有鉴定到对该酶具有高亲和力的特异性配体，所以使用硫酸铵级分，四种类型的柱层析和制备型Native-PAGE，不使用亲和柱层析进行纯化。我们希望协议将提供有用的信息用于纯化不能容易地使用亲和柱层析纯化的酶。
|