Li S S, Fitch W M, Pan Y C, Sharief F S
J Biol Chem. 1983 Jun 10;258(11):7029-32.
The amino acid sequence variation among seven lactate dehydrogenase isozymes from dogfish muscle, chicken muscle and heart, pig muscle and heart, and mouse and rat testes were compared with respect to the whole lactate dehydrogenase polypeptide chain as well as their four functional domains. The coenzyme-binding domain is more conserved than the substrate-binding domain. The sequence of the loop and helix alpha D region of testicular LDH-C4 isozymes is very different from those of somatic LDH-A4 and LDH-B4 isozymes, while the NH2-terminal arm is extremely variable. The most parsimonious phylogenetic tree among these seven vertebrate lactate dehydrogenase sequences clearly indicates that the LDH-A4 and LDH-B4 isozymes are more closely related to each other than either to the LDH-C4 isozymes.
比较了来自鲨鱼肌肉、鸡肌肉和心脏、猪肌肉和心脏以及小鼠和大鼠睾丸的七种乳酸脱氢酶同工酶在整个乳酸脱氢酶多肽链及其四个功能结构域方面的氨基酸序列变异。辅酶结合结构域比底物结合结构域更保守。睾丸乳酸脱氢酶C4同工酶的环区和αD螺旋区序列与体细胞乳酸脱氢酶A4和乳酸脱氢酶B4同工酶的序列非常不同，而氨基末端臂变化极大。这七种脊椎动物乳酸脱氢酶序列中最简约的系统发育树清楚地表明，乳酸脱氢酶A4和乳酸脱氢酶B4同工酶彼此之间的关系比它们与乳酸脱氢酶C4同工酶的关系更密切。
