Antifungal mechanism of SMAP-29 (1-18) isolated from sheep myeloid mRNA against Trichosporon beigelii.
The antifungal activity and mechanism of SMAP-29 (1-18) (SMAP-29), a cathelicidin-derived antimicrobial peptide deduced from N-terminal sequence of sheep myeloid mRNA, were investigated. SMAP-29 displayed a strong antifungal activity against various fungi. To understand the antifungal mechanism(s) of SMAP-29, we examined the interaction of SMAP-29 with the pathogenic fungus Trichosporon beigelii. Confocal microscopy showed that SMAP-29 was localized in the plasma membrane. The antifungal effects of SMAP-29 were further confirmed by using 1,6-diphenyl-1,3,5-hexatriene (DPH) as a plasma membrane probe. Flow cytometric analysis revealed that SMAP-29 acted in an energy-dependent manner. This interaction is also dependent on the ionic environment. Furthermore, SMAP-29 caused significant morphological changes when testing the membrane disrupting activity using liposomes (phosphatidylcholine/cholesterol; 10:1, w/w), as shown by scanning electron microscopy. The results suggest that SMAP-29 may exert its antifungal activity by disrupting the structure of cell membranes, via direct interaction with the lipid bilayers and irregularly disrupted fungal membranes in an energy- and salt-dependent manner.
Lee
Dong Gun
DG
Research Center for Proteineous Materials (RCPM), Chosun University, 375 Seosuk-Dong, Dong-Ku, Kwangju 501-759, Republic of Korea.
Kim
Pyoung Il
PI
Park
Yoonkyung
Y
Park
Seong-Cheol
SC
Woo
Eun-Rhan
ER
Hahm
Kyung-Soo
KS
D000818:Animals; D000935:Antifungal Agents / Q000494:pharmacology*; D001798:Blood Proteins / Q000737:chemistry* / Q000494:pharmacology*; D054804:Cathelicidins; D002462:Cell Membrane / Q000378:metabolism; D002469:Cell Separation; D004161:Diphenylhexatriene / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D016650:Fluorescein-5-isothiocyanate / Q000494:pharmacology; D005456:Fluorescent Dyes / Q000494:pharmacology; D007477:Ions; D008051:Lipid Bilayers / Q000378:metabolism; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D010452:Peptide Biosynthesis; D010455:Peptides / Q000737:chemistry; D012333:RNA, Messenger / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D012492:Salts; D012756:Sheep; D019810:Sodium Azide / Q000494:pharmacology; D014250:Trichosporon / Q000378:metabolism*
D000935:Antifungal Agents; D001798:Blood Proteins; D054804:Cathelicidins; D005456:Fluorescent Dyes; D007477:Ions; D008051:Lipid Bilayers; D010455:Peptides; D012333:RNA, Messenger; C403305:SMAP29 protein, Ovis aries; D012492:Salts; D004161:Diphenylhexatriene; D019810:Sodium Azide; D016650:Fluorescein-5-isothiocyanate