MOLECULAR-CLONING AND IDENTIFICATION OF A NOVEL PORCINE CATHELIN-LIKEANTIBACTERIAL PEPTIDE PRECURSOR

A novel clone (C6) encoding the precursor of a 79-residue proline/argi nine-rich antibacterial peptide prophenin was isolated from a porcine bone marrow cDNA library. Its deduced N-terminal propart shows 84% ide ntity with cathelin. Additionally, two cathelin isoforms were isolated from peripheral porcine blood and their N-termini sequenced. The sequ ence of one isoform corresponds to the cathelin sequence, whereas that of the other protein is identical to the propeptide of C6 clone. West ern blot analysis of total proteins from porcine and human bone marrow using polyclonal antibodies against cathelin revealed the presence of immunochemically related high molecular mass proteins of about 30 kDa in both samples, whereas low molecular mass proteins of approximately 12 kDa, corresponding to isolated cathelin, were not detected in huma n bone marrow.