Spleen antibacterial peptides: high levels of PR-39 and presence of two forms of NK-lysin

Abstract

Antibacterial peptides were isolated from porcine spleen by acetic acid extraction, ion exchange chromatography and reverse-phase high-performance liquid chromatography. C-terminal ladder sequence analysis of a bioactive peptide with matrix-assisted laser desorption/ionization mass spectrometry after digestion with carboxypeptidases P and Y showed that it is identical to the antibacterial proline/arginine-rich intestinal peptide PR-39. It is present at high levels in granulocytes of the spleen, and peptides with C-terminal proline amide and internal adjacent Pro residues can be analyzed with this method. In addition, two forms of NK-lysin (NKL) were found. One, NKLi, is identical to that isolated from pig intestine, and the other, NKLbw, to a mature peptide deduced from a clone from a porcine bone marrow cDNA library.

Characterization of a NK-lysin antimicrobial peptide gene from channel catfish

“…4). These results are consistent with known tissue expression of porcine NK-lysin which has been found in spleen, bone marrow, colon, and small intestine [10,37]. In both cases, expression seems to be limited to tissues that harbor lymphocyte populations.…”

Characterization of Bovine Homologues of Granulysin and NK-lysin

“…The bovine gene and the predicted gene product are polymorphic in nature. Variation in the porcine sequence is also evident from discrepancy between the reported gene product and amino acid sequence of protein isolated from porcine small intestine and spleen (2,30). Sequence analysis of different human donors, to date, indicates a single polymorphic site in the biologically active portion of the granulysin gene, resulting in a change from an isoleucine to a threonine (31).…”

The short proline-rich antibacterial peptide family

“…Peptide PR-39 was first isolated from pig intestine and showed antibacterial activity against E. coli and B. megaterium [57]. Later, similar porcine analogs were isolated from neurophils [58] and spleens [59]. Peptide PR-39 belongs to the proline-rich branch of the cathelicidin family of antibacterial peptides, one of the two major antibacterial families in mammals (the other is the defensin family) [60].…”

“…Vol. 59,2002 Review Article 1139 skin secretions [20], moricin, from Bombyx mori, apparently does not resemble any other antibacterial peptide [21]. In general, all antimicrobial peptides interact with the bacterial cell membrane.…”