Related Experiment Video
Updated: Jul 10, 2026

Production, Crystallization and Structure Determination of C. difficile PPEP-1 via Microseeding and Zinc-SAD
Published on: December 30, 2016
Paecilopeptin, a new cathepsin S inhibitor produced by Paecilomyces carneus
Kazutoshi Shindo1, Hidefumi Suzuki, Toru Okuda
1Department of Food and Nutrition, Japan Women's University, 2-8-1 Mejirodai, Bunkyo-ku, Tokyo 112-8681, Japan. kshindo@fc.jwu.ac.jp
Abstract:
Paecilopeptin, a novel cathepsin S inhibitor, was produced and isolated from the culture supernatant of the fungal strain, Paecilomyces carneus. A spectroscopic analysis revealed the planar structure of paecilopeptin to be acetyl-Leu-Val-CHO. The stereochemistry of the constituent amino acids was analysed by chiral HPLC after oxidation and 6N HCl hydrolysis of paecilopeptin. The total synthesis of paecilopeptin was completed in six steps. Paecilopeptin inhibited human cathepsin S with an IC50 value of 2.1 nM in vitro.

