Structure of hypothalamic coronaro-constrictory peptide factors.

The following peptide structure in 3 of 5 coronaro-constrictory peptide factors isolated from bovine hypothalamus was determined by amino acid analysis and Edman degradation: 1) (P1)--Val-Val-Tyr-Pro-Trp; 2) (P2)--Val-Val-Tyr-Pro-Trp-Thr; 3) (P3)--Leu-Val-Val-Tyr-Pro-Trp-Thr. A computer search for these amino acid sequences revealed that these peptides represent fragments 33-37; 33-38; 32-38 of the beta-chain of bovine hemoglobin. Solid phase peptide synthesis of 2 peptides (P2 and P3) was carried out. It was established that synthetic peptides had the properties of coronaro-constrictory peptides. The possibility of the formation of hypothalamic coronaro-constrictory peptides in vivo is discussed.