Abe K, Kimura S, Kizawa R, Anan F K, Sugita Y
J Biochem. 1985 Jun;97(6):1659-68. doi: 10.1093/oxfordjournals.jbchem.a135224.
The amino acid sequences of human, porcine, and bovine erythrocyte cytochromes b5 which are soluble and present in the cytosol have been determined. In addition, the partial sequences of microsome-bound liver cytochrome b5, namely the sequence of the N-terminal region and joint region between the heme-containing and membranous part, have been established for human and porcine sources. All the cytochromes b5 from erythrocyte and liver contained N-acetylated N-termini. Of the 97 amino acid residues of erythrocyte cytochrome b5, residues 1-96 were identical with those of the liver protein of the same species. However, residue 97 (C-terminal residue) was proline for human erythrocyte cytochrome b5 and serine for the porcine protein, while residues 97 (joint region) of human and porcine liver cytochromes b5 were threonine. These findings indicate that the two forms of cytochrome b5 are encoded by two different but closely related mRNAs.
已确定人、猪和牛红细胞中可溶且存在于细胞质中的细胞色素b5的氨基酸序列。此外，还确定了人源和猪源微粒体结合型肝细胞色素b5的部分序列，即含血红素部分与膜部分之间的N端区域和连接区域的序列。红细胞和肝脏中的所有细胞色素b5都含有N - 乙酰化的N端。红细胞细胞色素b5的97个氨基酸残基中，第1 - 96个残基与同物种肝脏蛋白的残基相同。然而，人红细胞细胞色素b5的第97个残基（C端残基）是脯氨酸，猪蛋白的是丝氨酸，而人源和猪源肝细胞色素b5的第97个残基（连接区域）是苏氨酸。这些发现表明，细胞色素b5的两种形式由两种不同但密切相关的mRNA编码。
