pr-39 and Leukemia--T-Cell

PR-39, a proline/arginine-rich peptide antibiotic, has been purified from pig intestine and later shown to originate in the bone marrow. Intending to isolate a clone for a human counterpart to PR-39, we synthesized a PCR probe derived from the PR-39 gene. However, when this probe was used to screen a human bone marrow cDNA library, eight clones were obtained with information for another putative human peptide antibiotic, designated FALL-39 after the first four residues. FALL-39 is a 39-residue peptide lacking cysteine and tryptophan. All human peptide antibiotics previously isolated (or predicted) belong to the defensin family and contain three disulfide bridges. The clone for prepro-FALL-39 encodes a cathelin-like precursor protein with 170 amino acid residues. We have postulated a dibasic processing site for the mature FALL-39 and chemically synthesized the putative peptide. In basal medium E, synthetic FALL-39 was highly active against Escherichia coli and Bacillus megaterium. Residues 13-34 in FALL-39 can be predicted to form a perfect amphiphatic helix, and CD spectra showed that medium E induced 30% helix formation in FALL-39. RNA blot analyses disclosed that the gene for FALL-39 is expressed mainly in human bone marrow and testis.

Topics: Adult; Amino Acid Sequence; Animals; Anti-Bacterial Agents; Anti-Infective Agents; Antimicrobial Cationic Peptides; Base Sequence; Blotting, Northern; Bone Marrow; Child; Cloning, Molecular; Cysteine; DNA Primers; DNA, Complementary; Female; Gene Expression; Gene Library; Humans; Leukemia, T-Cell; Male; Molecular Sequence Data; Organ Specificity; Peptide Biosynthesis; Peptides; Protein Structure, Secondary; RNA; RNA, Messenger; Sequence Homology, Amino Acid; Swine; Testis