期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1987
卷号：84
期号：2
页码：575-579
DOI：10.1073/pnas.84.2.575
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：An unusual crustacean cardioactive peptide (CCAP) from the pericardial organs of the shore crab Carcinus maenas has been purified to homogeneity by a two-step reversed-phase HPLC procedure. Manual microsequencing using the 4-(N,N-dimethylamino)azobenzene 4'-isothiocyanate/phenylisothiocyanate double-coupling technique and automated gas-phase sequencing of the oxidized peptide revealed that CCAP is a nonapeptide (Mr 957) of the sequence Pro-Phe-[unk]Cys-Asn-Ala-Phe-Thr-Gly-Cys-NH2. We have confirmed the sequence by chemical synthesis of the C-terminally amidated and nonamidated forms of the peptide. The presence of the amide group was indicated by lack of susceptibility to carboxypeptidase A and Y treatment and was confirmed by the observation that the native CCAP comigrated with the amidated synthetic peptide on HPLC. Native and synthetic CCAP displayed high accelerating activity on a semi-isolated crab heart preparation, whereas the nonamidated synthetic peptide was of much lower potency. The effect of CCAP was both inoand chronotropic. The two pericardial organs of one animal yielded 30-40 pmol of extractable CCAP. Its sequence does not resemble that of any known neuropeptide. However, a "mirror-image" similarity to vasopressin is conspicuous.
