Antimicrobial peptides exhibit varied behavior and destabilize cellular membranes. In collaboration with B. Bishop (George Mason Chemistry and Biochemistry), we have investigated the interactions of cationic antimicrobial peptides (CAMPs) and membranes.  My research group has focused on dissecting the behavior and mechanism of these peptides, using fluorescence microscopy to visualize their binding and lysis activity on vesicles.  From these efforts, we have observed differences in behavior between the parent peptide, NA CATH (34 amino acids, +15 net charge), and two isomers (L and D, 11 amino acids, +8 net charge) of a shortened sequence which is derived from the parent.  The efficacy of the D isomer is of particular importance because incorporating D amino acids have proven successful in prolonging the lifetime of peptides against proteases from the microbial target.  These antimicrobial peptides are a promising alternative to traditional antibiotics against multidrug resistant bacteria.  Our studies show that variations in CAMPs in terms of length and chirality do not affect potency.  Due to the increased lysing observed in the case of the NA CATH and L-isomer v. primarily membrane leakage for the D-isomer, we have pursued kinetic (fluorescence spectroscopy) and structural (NMR) studies of the parent and with similar plans for the shortened isomers.  Our structural studies are in collaboration with M. Massiah (GW Chemistry).