title: Staphylocidal action of thrombin-induced platelet microbicidal protein is not solely dependent on transmembrane potential.
abstract: Thrombin-induced platelet microbicidal protein (tPMP) is a small, cationic, antimicrobial peptide released from rabbit platelets when stimulated with thrombin. We studied the relationship between staphylococcal transmembrane potential (delta psi) and tPMP staphylocidal activity. A genetically related pair of Staphylococcus aureus strains, 6850 and JB1, which differ in delta psi generation (-143 and -97 mV, respectively) were used. Mutant JB-1 was substantially less susceptible to tPMP than the parental strain, 6850. Menadione supplementation, which normalized the delta psi of strain JB-1, did not restore JB-1 tPMP susceptibility. These findings suggest that the staphylocidal activities of tPMP require factors other than or in addition to an intact delta psi.
authors.affiliation: Department of Medicine, Division of Infectious Diseases, St. John's Cardiovascular Research Center, LAC-Harbor UCLA Medical Center, Torrance, California 90509, USA.
authors.forename: S P
authors.initials: SP
authors.lastname: Koo
authors.forename: A S
authors.initials: AS
authors.lastname: Bayer
authors.forename: H G
authors.initials: HG
authors.lastname: Sahl
authors.forename: R A
authors.initials: RA
authors.lastname: Proctor
authors.forename: M R
authors.initials: MR
authors.lastname: Yeaman
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001798:Blood Proteins / Q000494:pharmacology*; D008564:Membrane Potentials; D008826:Microbial Sensitivity Tests; D011817:Rabbits; D013210:Staphylococcus / Q000187:drug effects* / Q000502:physiology; D013917:Thrombin / Q000494:pharmacology*; D014812:Vitamin K / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D001798:Blood Proteins; C077150:platelet microbicidal protein, Oryctolagus cuniculus; D014812:Vitamin K; D013917:Thrombin