Ranacyclin-NF, a Novel Bowman–Birk Type Protease Inhibitor from the Skin Secretion of the East Asian Frog, Pelophylax nigromaculatus

Tao Wang, Yangyang Jiang, Xiaoling Chen, Lei Wang, Chengbang Ma, Xinping Xi, Yingqi Zhang, Tianbao Chen, Christopher Shaw, Mei Zhou

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)
32 Downloads (Pure)

Abstract

Serine protease inhibitors are found in plants, animals and microorganisms, where they play important roles in many physiological and pathological processes. Inhibitor scaffolds based on natural proteins and peptides have gradually become the focus of current research as they tend to bind to their targets with greater specificity than small molecules. In this report, a novel Bowman–Birk type inhibitor, named ranacyclin-NF (RNF), is described and was identified in the skin secretion of the East Asian frog, Pelophylax nigromaculatus. A synthetic replicate of the peptide was subjected to a series of functional assays. It displayed trypsin inhibitory activity with an inhibitory constant, Ki, of 447 nM and had negligible direct cytotoxicity. No observable direct antimicrobial activity was found but RNF improved the therapeutic potency of Gentamicin against Methicillin-resistant Staphylococcus aureus (MRSA). RNF shared significant sequence similarity to previously reported and related inhibitors from Odorrana grahami (ORB) and Rana esculenta (ranacyclin-T), both of which were found to be multi-functional. Two analogues of RNF, named ranacyclin-NF1 (RNF1) and ranacyclin-NF3L (RNF3L), were designed based on some features of ORB and ranacyclin-T to study structure–activity relationships. Structure–activity studies demonstrated that residues outside of the trypsin inhibitory loop (TIL) may be related to the efficacy of trypsin inhibitory activity.
Original languageEnglish
Article number149
Number of pages15
JournalBiology
Volume9
Issue number7
Early online date02 Jul 2020
DOIs
Publication statusPublished - 2020

Keywords

  • Bowman–Birk inhibitor; ranacyclin; trypsin inhibitor; structure–activity relationship; synergistic effect; Gentamicin

Fingerprint

Dive into the research topics of 'Ranacyclin-NF, a Novel Bowman–Birk Type Protease Inhibitor from the Skin Secretion of the East Asian Frog, Pelophylax nigromaculatus'. Together they form a unique fingerprint.

Cite this