Quantitative interactions between cryptdin-4 amino terminal variants and membranes.
Paneth cells secrete alpha-defensins into the lumen from the base of small intestinal crypts, and cryptdin-4 (Crp4) is the most potent mouse alpha-defensin in vitro. Purified recombinant Crp4 and Crp4 variants with (des-Gly)-, (Gly1Val)-, (Gly1Asp)-, and (Gly1Arg)-substitutions were all bactericidal with Crp4 and (Gly1Arg)-Crp4 being slightly more active than other variants. Bactericidal activities correlated directly with permeabilization of live Escherichia coli, with equilibrium binding to E. coli membrane phospholipid bilayers and vesicles, and with induced graded fluorophore leakage from phospholipid vesicles. The Crp4 peptide N-terminus affects bactericidal activity modestly, apparently by influencing peptide binding to phospholipid bilayers and subsequent permeabilization of target cell membranes.
Satchell
Donald P
DP
Department of Pathology, College of Medicine, University of California, Irvine, CA 92697-4800, USA.
Sheynis
Tanya
T
Kolusheva
Sofiya
S
Cummings
Jason
J
Vanderlick
T Kyle
TK
Jelinek
Raz
R
Selsted
Michael E
ME
Ouellette
Andre J
AJ
D000114:Acetylene / Q000031:analogs & derivatives* / Q000378:metabolism; D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism*; D002463:Cell Membrane Permeability / Q000187:drug effects; D005658:Fungi / Q000187:drug effects; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D008081:Liposomes / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D010743:Phospholipids / Q000378:metabolism; D000078789:Polyacetylene Polymer; D011108:Polymers / Q000378:metabolism; D053279:Polyynes; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D023084:alpha-Defensins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology
D008081:Liposomes; D010743:Phospholipids; D000078789:Polyacetylene Polymer; D011108:Polymers; D011994:Recombinant Proteins; D023084:alpha-Defensins; C401847:cryptdin 4, mouse; D053279:Polyynes; C082361:polydiacetylene; D000114:Acetylene