Characterization of PdCP1, a serine carboxypeptidase from Pseudogymnoascus destructans, the causal agent of White-nose Syndrome.

Beekman, Chapman; Jiang, Zhenze; Suzuki, Brian M.; Palmer, Jonathan M.; Lindner, Daniel L.; O'Donoghue, Anthony J.; Knudsen, Giselle M.; Bennett, Richard J.

Pseudogymnoascus destructans is a pathogenic fungus responsible for White-nose Syndrome (WNS), a disease afflicting multiple species of North American bats. Pseudogymnoascus destructans infects susceptible bats during hibernation, invading dermal tissue and causing extensive tissue damage. In contrast, other Pseudogymnoascus species are non-pathogenic and cross-species comparisons may therefore reveal factors that contribute to virulence. In this study, we compared the secretome of P. destructans with that from several closely related Pseudogymnoascus species. A diverse set of hydrolytic enzymes were identified, including a putative serine peptidase, PdCP1, that was unique to the P. destructans secretome. A recombinant form of PdCP1 was purified and substrate preference determined using a multiplexed-substrate profiling method based on enzymatic degradation of a synthetic peptide library and analysis by mass spectrometry. Most peptide substrates were sequentially truncated from the carboxyl-terminus revealing that this enzyme is a bona fide carboxypeptidase. Peptides with arginine located close to the carboxyl-terminus were rapidly cleaved, and a fluorescent substrate containing arginine was therefore used to characterize PdCP1 activity and to screen a selection of peptidase inhibitors. Antipain and leupeptin were found to be the most potent inhibitors of PdCP1 activity.

CARBOXYPEPTIDASES; PSEUDOGYMNOASCUS destructans; WHITE-nose syndrome; HIBERNATION; ARGININE

Biological Chemistry, 2018, Vol 399, Issue 12, p1375

1431-6730

Academic Journal

10.1515/hsz-2018-0240