SYNTHETIC PEPTIDE COMBINATORIAL LIBRARIES - A METHOD FOR THE IDENTIFICATION OF BIOACTIVE PEPTIDES AGAINST PHYTOPATHOGENIC FUNGI

Synthetic combinatorial libraries were evaluated with an iterative pro cess to identify a hexapeptide with broad-spectrum activity against se lected phytopathogenic fungi. A D-amino acid hexapeptide (FRLKFH) and pentapeptide (FRLHF) exhibited activity against Fusarium oxysporum f. sp, lycopersici, Rhizoctonia solani (anastomosis group 1), Ceratocysti s fagacearum, and Pythium ultimum, The peptides showed no hemolytic or mutagenic activity, Fluorescent microscopy studies with a membrane im permeant dye indicated that fungal cytoplasmic membranes were compromi sed rapidly and that the nuclear membrane was also affected.