Hamilton J W, Niall H D, Jacobs J W, Keutmann H T, Potts J T, Cohn D V
Proc Natl Acad Sci U S A. 1974 Mar;71(3):653-6. doi: 10.1073/pnas.71.3.653.
Proparathyroid hormone (calcemic fraction-A) is a biosynthetic precursor of parathyroid hormone in bovine glands. Limited amounts of the isolated prohormone have been obtained for the purpose of initial structural studies. The results of automated sequence analysis on two separate preparations indicate that the N-terminal region of the prohormone consists of the sequence Lys-Ser-Val-Lys-Lys-Arg followed by a sequence exactly corresponding to residues 1 to 34 of bovine parathyroid hormone. Also observed was a minor sequence (about 12% of the total) in which the N-terminal lysine was absent. These data suggest that more than one species of prohormone may exist. Due to the small quantities of sample available, the analyses were restricted to the N-terminal portion of the prohormone only. However, because the amino-acid composition of the prohormone indicates it to be a molecule containing more than 100 amino acids, the possibility remains that additional residues occur at the C-terminus. Thus, the prohormone structure based on these data is believed to consist of the hexapeptide sequence above, followed by the known sequence of the 84 residues in parathyroid hormone, possibly followed by an additional sequence of 10-15 residues.
甲状旁腺激素原（血钙调节部分-A）是牛甲状旁腺中甲状旁腺激素的生物合成前体。为了进行初步的结构研究，已获得了少量分离出的前激素。对两种不同制剂进行自动序列分析的结果表明，前激素的N端区域由Lys-Ser-Val-Lys-Lys-Arg序列组成，其后是与牛甲状旁腺激素第1至34位残基完全对应的序列。还观察到一个次要序列（约占总数的12%），其中N端赖氨酸缺失。这些数据表明可能存在不止一种前激素。由于可用样品量少，分析仅限于前激素的N端部分。然而，由于前激素的氨基酸组成表明它是一个含有100多个氨基酸的分子，C端仍有可能存在其他残基。因此，基于这些数据的前激素结构被认为由上述六肽序列组成，其后是甲状旁腺激素中84个残基的已知序列，可能再后面是10 - 15个残基的附加序列。
