Crossley L G, Jago G R, Davidson B E
Biochim Biophys Acta. 1979 Dec 14;581(2):342-55. doi: 10.1016/0005-2795(79)90254-x.
The following amino acid sequence information has been determined for the fructose 1,6-bisphosphate-dependent lactate dehydrogenase from Streptococcus cremoris US3: the C-terminal amino acid, the N-terminal sequence of the first 20 amino acids and the sequence of a 53-residue tryptic peptide containing the only cysteine residue in the protein. The enzyme was cleaved by alkali at the cysteine residue following reaction first with 5,5'-dithiobis(2-nitrobenzoic acid) and then with K14CN. This treatment yielded two cleavage products as well as some higher polymers and some uncleaved enzyme. The radioactive cleavage product was purified and its size indicated that the cysteine residue is 80 residues from the C-terminus. Comparisons of the sequences determined for the S. cremoris enzyme with those already known for dogfish lactate dehydrogenase indicate that the two enzymes are only distantly related since the sequence homology between them is limited and of borderline statistical significance.
已确定来自嗜热链球菌US3的1,6 - 二磷酸果糖依赖性乳酸脱氢酶的以下氨基酸序列信息：C末端氨基酸、前20个氨基酸的N末端序列以及包含该蛋白质中唯一半胱氨酸残基的53个残基胰蛋白酶肽段的序列。该酶首先与5,5'-二硫代双（2 - 硝基苯甲酸）反应，然后与K14CN反应，之后在半胱氨酸残基处被碱切割。这种处理产生了两种切割产物以及一些更高的聚合物和一些未切割的酶。对放射性切割产物进行了纯化，其大小表明半胱氨酸残基距离C末端80个残基。将嗜热链球菌酶的序列与已知的角鲨乳酸脱氢酶序列进行比较表明，这两种酶的亲缘关系较远，因为它们之间的序列同源性有限且具有临界统计学意义。
