Structural insight into the CUB2 domain’s role in enteropeptidase-mediated trypsinogen activation

Q Qiuyue Song (Department of Gastroenterology, Shanghai Institute of Pancreatic Diseases, Changhai Hospital, Navy/Second Military Medical University) L Lisi Peng (Department of Gastroenterology, Shanghai Institute of Pancreatic Diseases, Changhai Hospital, Navy/Second Military Medical University) X Xiaoli Yang (Department of Gastroenterology, Shanghai Institute of Pancreatic Diseases, Changhai Hospital, Navy/Second Military Medical University) J Jiaheng Xu (Department of Gastroenterology, Shanghai Institute of Pancreatic Diseases, Changhai Hospital, Navy/Second Military Medical University) D Deyu Zhang (Department of Gastroenterology, Shanghai Institute of Pancreatic Diseases, Changhai Hospital, Navy/Second Military Medical University) X Xiaorong Tian (Department of Gastroenterology, Shanghai Institute of Pancreatic Diseases, Changhai Hospital, Navy/Second Military Medical University) S Shiyu Li (Department of Gastroenterology, Shanghai Institute of Pancreatic Diseases, Changhai Hospital, Navy/Second Military Medical University) Y Yang Zhang B Baoan Ji (Department of Cancer Biology, Mayo Clinic in Florida) Z Zhendong Jin (Department of Gastroenterology, Shanghai Institute of Pancreatic Diseases, Changhai Hospital, Navy/Second Military Medical University) Z Zhanyu Ding (Department of Gastroenterology, Shanghai Institute of Pancreatic Diseases, Changhai Hospital, Navy/Second Military Medical University) Z Zhaoshen Li (Department of Gastroenterology, Shanghai Institute of Pancreatic Diseases, Changhai Hospital, Navy/Second Military Medical University) H Haojie Huang (Department of Urology, The First Affiliated Hospital, Zhejiang University School of Medicine)

Abstract

Elucidating the structure and function of enteropeptidase (EP) is essential for advancing our understanding of its biological significance, particularly in regulating trypsinogen activation. Using cryo-EM and enzymatic activity, we uncovered the significance of the CUB2 domain in mediating the cleavage of macromolecular substrates. We identified crucial binding loops and key residues for EP’s proteolytic function. The mutation E574A enhanced the proteolytic activity of EP, whereas the mutation N619A diminished its cleavage efficiency, highlighting the importance of surface-charged interactions in modulating EP’s activity. A proteolytic cycle was proposed to deepen our understanding of the trypsinogen activation by EP. This work offers valuable insights into the molecular mechanisms underlying EP’s interaction with its substrate, and opens up avenues for therapeutically modulating EP-mediated proteolysis.

Article Details

Volume / Issue Vol. 123, Issue 12
Published March 24, 2026
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (13)

Q

Qiuyue Song

Department of Gastroenterology, Shanghai Institute of Pancreatic Diseases, Changhai Hospital, Navy/Second Military Medical University

L

Lisi Peng

Department of Gastroenterology, Shanghai Institute of Pancreatic Diseases, Changhai Hospital, Navy/Second Military Medical University

X

Xiaoli Yang

Department of Gastroenterology, Shanghai Institute of Pancreatic Diseases, Changhai Hospital, Navy/Second Military Medical University

J

Jiaheng Xu

Department of Gastroenterology, Shanghai Institute of Pancreatic Diseases, Changhai Hospital, Navy/Second Military Medical University

D

Deyu Zhang

Department of Gastroenterology, Shanghai Institute of Pancreatic Diseases, Changhai Hospital, Navy/Second Military Medical University

X

Xiaorong Tian

Department of Gastroenterology, Shanghai Institute of Pancreatic Diseases, Changhai Hospital, Navy/Second Military Medical University

S

Shiyu Li

Department of Gastroenterology, Shanghai Institute of Pancreatic Diseases, Changhai Hospital, Navy/Second Military Medical University

Y

Yang Zhang

B

Baoan Ji

Department of Cancer Biology, Mayo Clinic in Florida

Z

Zhendong Jin

Department of Gastroenterology, Shanghai Institute of Pancreatic Diseases, Changhai Hospital, Navy/Second Military Medical University

Z

Zhanyu Ding

Department of Gastroenterology, Shanghai Institute of Pancreatic Diseases, Changhai Hospital, Navy/Second Military Medical University

Z

Zhaoshen Li

Department of Gastroenterology, Shanghai Institute of Pancreatic Diseases, Changhai Hospital, Navy/Second Military Medical University

H

Haojie Huang

Department of Urology, The First Affiliated Hospital, Zhejiang University School of Medicine