Prophenin‐1, an exceptionally proline‐rich antimicrobial peptide from porcine leukocytes

Abstract

We purified and characterized an unusual antimicrobial peptide, prophenin-1 (PF-I), from porcine leukocytes. The peptide had a mass of 8,683 and contained 79 residues, including 42 (53.2%) prolines and 15 (19.0%) phenylalanines. Its N-terminal 60 residues consisted of three perfect and three nearly perfect repeats of a decamer, FPPPNFPGPR. Prophenin-I was encoded on a cathelin-containing precursor and showed substantially more activity against E. coli, a Gram-negative bacterium, than against Listeria monocytogenes, a Gram-positive organism, in vitro.

Cathelicidins: a novel protein family with a common proregion and a variable C‐terminal antimicrobial domain

“…Peptides corresponding to all known sequences have either been purified from natural sources [13,[34][35][36][37][38][39], after processing of the respective precursors, or have been obtained by chemical synthesis based on the sequence deduced from cDNA [26,27,29,32,33]. At present they include rabbit CAPI8(106 142) [39], human FALL-39/CAP18 [32,33], PMAP-36 [26] and PMAP-37 [29], all of which are mostly s-helical; two Trpcontaining peptides, indolicidin [36] and PMAP-23 [27]; the Pro-and Arg-rich Bac5 [12], Bac7 [12], PR-39 [13] and prophenin [38]; the cyclic dodecapeptide [34] and protegrins [37] which are loop-forming molecules with one and two disulfide bonds, respectively. The sequence of the Pro-and Arg-rich peptides (Fig.…”

“…The sequence of the Pro-and Arg-rich peptides (Fig. 1) is peculiar in that several short modules are present, and often arranged in tandem repeats [12,13,38]. The structure of some of these peptides has been analyzed by circular dichroism spectroscopy, showing that PMAP-36 [26], PMAP-37 [29] and FALL-39 [32] undergo a transition from a random coil to an ordered, mainly s-helical conformation on addition of an organic solvent.…”

“…The Pro-and Arg-rich peptides are substantially more active against gram-negative than gram-positive bacteria [13,35,38]. Conversely, the other linear (helical and Trp-rich) and Cys-containing peptides are in general highly active against both gram-positive and gramnegative microorganisms [26,27,32,34,36,37,49].…”

cDNA sequences of three sheep myeloid cathelicidins

“…This region is followed in the sequence of Bac7 by three tandemly repeated tetradecamers which are not present in the sequence of Bac7.5, although short regions of similarity, including several PRP repeats, can be noted. PRP repeats, and other proline-rich repeats are often observed in the Pro-and Arg-rich antimicrobial peptides [27,28,37] and are likely to influence their structure. Recent studies indicate that this type of peptide may adopt conformations similar to the polyproline type II helix [39~10].…”

Structural and functional characterization of CATH_BRALE, the defense molecule in the ancient salmonoid, Brachymystax lenok

“…Other examples of tandem repeats have also been observed in some mammalian cathelicidins, in particular, the proline-rich peptides Bac7, Bac5, PR-39 and prophenins from cow and pig, showing typical and different proline-containing repeated motifs throughout their sequences [26,27]. On the other hand, CATH_BRALE contains high level of glycines (30% of the entire residues).…”