Investigation of amino acid sequence of specific ouabain conjugated peptides

AIM: The purpose of the study was to investigate the gene and amino acid sequence of specific ouabain conjugated peptides (OCP) in order to get an experimental bases to block or antagonist the actions between endogenous ouabain(EO) and sodium pump in hypertension. METHODS: Screening the phage displayed 12-peptide library by biopaning for OCP. The sequence of each selected peptide was determined and the sequence was analyzed through internet. The bioactivity was determined by erythrocyte [ 86 Rb] uptaking. RESULTS: Three kinds of peptides were screened out. Peptide A (12 peptide) was occupied in 66 7%(8/12), peptide B (8 peptide) 16 7% (2/12) and peptide C (12 peptide) 8 3% (1/12). There was only one case without insertron. The analysis of protein showed that there were no homogenous between peptide A, B, C and sodium pump. The amino acid sequence of specific OCP was Leu-Leu-Ala-Asp-Thr-Thr-His-His-Arg -Pro-Trp-Thr. CONCLUSIONS: Determination of the sequence of OCP supplies an important experimental foundation for ouabain research. The results also show that phage display peptide library is an effective, simple and efficient method to select specific steroid receptors. [