Niall H D, Hogan M L, Sauer R, Rosenblum I Y, Greenwood F C
Proc Natl Acad Sci U S A. 1971 Apr;68(4):866-70. doi: 10.1073/pnas.68.4.866.
Human placental lactogen has been found to resemble human pituitary growth hormone very closely in amino acid sequence, about 80% of the residues examined being identical in the two molecules when a revised sequence for growth hormone is used as the basis for comparison. The structural features responsible for the differing biological potency of the two hormones may therefore reside in rather limited regions of primary structure. The observation of internal sequence homologies within the pituitary growth hormone and prolactin and the placental lactogen molecules suggests that these polypeptide hormones may have evolved by genetic reduplication from a smaller common ancestral peptide. This finding directs further attention to subfragments of these molecules as possible possessors of intrinsic somatotrophic and lactogenic activity.
已发现人胎盘催乳素在氨基酸序列上与人生长激素极为相似。若以修订后的生长激素序列作为比较基础,在这两种分子中,约80%经检测的残基是相同的。因此,这两种激素生物活性不同的结构特征可能存在于一级结构中相当有限的区域。对垂体生长激素、催乳素及胎盘催乳素分子内部序列同源性的观察表明,这些多肽激素可能是通过基因复制从一个较小的共同祖先肽进化而来的。这一发现进一步引导人们关注这些分子的亚片段,它们可能具有内在的促生长和催乳活性。