title: Structural and functional characterization of the porcine proline-rich antifungal peptide SP-B isolated from salivary gland granules.
abstract: A 1905-Da cationic proline-rich peptide, named SP-B, was recently isolated by our group as the main component of salivary gland granules, and its primary sequence fully characterized by means of automated Edman sequencing and LC-MS/MS tools. In the present study SP-B is shown to possess antifungal activity when challenged with strains of Cryptococcus neoformans, Candida albicans and Aspergillus fumigatus, while only negligible antibacterial activity was detected. Furthermore, SP-B was found to be non-cytotoxic when tested on fibroblast cell lines. To obtain information regarding its structure affinity, capillary electrophoresis (CE), circular dichroism (CD) and attenuated total reflection (ATR)-FT/IR experiments were performed. CE revealed a pH dependence of the hydrodynamic radial dimensions both in aqueous and 2,2,2-trifluoroethanol solutions. CD and ATR-FT/IR measurements confirmed the structure-pH relationship, revealing a secondary structure composed of mixed proportions of polyproline-II, unordered and turn motifs, the last being more evident in the zwitterionic form of the peptide. From these findings SP-B peptide could be classified as a new member of the proline-rich antimicrobial peptide family.
authors: Department of Sciences Applied to Biosystems, University of Cagliari, Cittadella Universitaria, Monserrato I-09042, Cagliari, Italy.
authors: T
authors: T
authors: Cabras
authors: R
authors: R
authors: Longhi
authors: F
authors: F
authors: Secundo
authors: G
authors: G
authors: Nocca
authors: S
authors: S
authors: Conti
authors: L
authors: L
authors: Polonelli
authors: C
authors: C
authors: Fanali
authors: R
authors: R
authors: Inzitari
authors: R
authors: R
authors: Petruzzelli
authors: I
authors: I
authors: Messana
authors: M
authors: M
authors: Castagnola
authors: A
authors: A
authors: Vitali
mesh_terms: D000818:Animals; D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D004745:Enkephalins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D011392:Proline / Q000737:chemistry*; D011498:Protein Precursors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D012469:Salivary Glands / Q000737:chemistry*; D034421:Sus scrofa
chemical_list: D000935:Antifungal Agents; D004745:Enkephalins; D011498:Protein Precursors; C056943:peptide B; D011392:Proline