Selection of Burkholderia pseudomallei protease-binding peptides by phage display

Burkholderia pseudomallei is a causative agent of melioidosis, a fatal comm unity acquired septicemia in Southeast Asia and Northern Australia. A prote ase has been proposed to be one of the major pathogenic factors to play a s ignificant role in melioidosis. We have used phage display technology to id entify peptides binding to B. pseudomallei protease. By screening a constra ined cyclic heptapeptide library, five independent clones with affinity to this protease were isolated and the amino acid sequences were determined. T he cyclic heptapeptides from two of the phage clones (Cys-Phe-Phe-Met-Pro-H is-Thr-Phe-Cys) were identical and showed the strongest phage-protease inte raction as detected by ELISA. Four of the five selected phages at the amoun t of 10(13) phages could inhibit B. pseudomallei protease activity by appro ximately 50%.