Complete Amino Acid Sequences of a Pair of Fish (Tilapia) Prolactins, tPRL₁₇₇ and tPRL₁₈₈

Authors

Kazuo Yamaguchi
Jennifer L. Specker, University of Rhode Island
David S. King
Yoshiharu Yokoo
Richard S. Nishioka
Tetsuya Hirano
Howard A. Bern

Document Type

Article

Date of Original Version

1988

Department

Zoology

Abstract

The complete amino acid sequences of a pair of tilapia (Oreochromis mossambicus) prolactins (PRLs) were determined. The larger PRL of molecular mass 20,836 Da consists of 188 amino acid residues. The smaller PRL of molecular mass 19,584 Da is 11 residues shorter. On alignment of the two sequences, the 19.6-kDa PRL (tPRL₁₇₇) has two conspicuous deletions on the NH_2- terminal side of the disulfide bond which connects the first and second cysteine residues. The degree of similarity between the two PRL sequences is unexpectedly low (130 identical residues, 69%) compared with that between the variants of other teleostean PRLs. Circular dichroism spectra and hydropathy profiles suggest structural similarity of the two PRLs. The sequence of the 20.8-kDa PRL (tPRL₁₈₈) has 69% identity with that of salmon PRL. The sequence of tPRL₁₇₇ is 56% identical with that of salmon PRL. Each tilapia PRL is equally similar to mammalian PRLs (about 30% identical residues). Regions highly conserved among teleostean and mammalian PRLs were identified on the COOH-terminal side of the disulfide bond connecting the first and second cysteine residues.

Citation/Publisher Attribution

Yamaguchi, K., Specker, J. L., King, D. S., Yojoo, Y., Nichioka, R. S., Hirano, T., & Bern, H. A. (1988). Complete Amino Acid Sequences of a Pair of Fish (Tilaplia) Prolactins, tPRL₁₇₇ and tPRL₁₈₈*. The Journal of Biological Chemistry, 263(19), 9113-9121. Retrieved from http://www.jbc.org/content/263/19/9113.

Available at: http://www.jbc.org/content/263/19/9113