Maeda N, Fitch W M
J Biol Chem. 1981 May 10;256(9):4301-9.
Myoglobin was purified from a muscle extract of lace monitor lizard, Varanus varius, by Sephadex G-75, followed by DEAE-cellulose column chromatography. The apomyoglobin was cleaved with cyanogen bromide. The largest fragment was further digested with pepsin, trypsin, and alpha-chymotrypsin. From the amino acid sequence of the cyanogen bromide fragments, together with those of tryptic peptides of apomyoglobin, the complete amino acid sequence of lizard myoglobin was deduced. To investigate the tetrapod and amniote origins, many possible phylogenetic trees were constructed using the myoglobin sequences, including those of map turtle and lace monitor lizard. The tree that requires the minimum number of nucleotide substitutions in their genes for the myoglobin sequences to have evolved from a common ancestor was different from the similarly most parsimonious trees for cytochrome c or for alpha-hemoglobin. The trees were different from each other and from the tree that best reflects current biological opinions.
通过葡聚糖凝胶G-75，接着进行DEAE-纤维素柱色谱法，从蕾丝巨蜥（Varanus varius）的肌肉提取物中纯化出肌红蛋白。脱辅基肌红蛋白用溴化氰裂解。最大的片段再用胃蛋白酶、胰蛋白酶和α-糜蛋白酶消化。根据溴化氰片段的氨基酸序列，以及脱辅基肌红蛋白的胰蛋白酶肽段的氨基酸序列，推导出蜥蜴肌红蛋白的完整氨基酸序列。为了研究四足动物和羊膜动物的起源，使用肌红蛋白序列构建了许多可能的系统发育树，包括地图龟和蕾丝巨蜥的序列。对于肌红蛋白序列从共同祖先进化而来，其基因中需要最少核苷酸替换数的树，与细胞色素c或α-血红蛋白的类似最简约树不同。这些树彼此不同，也与最能反映当前生物学观点的树不同。
