Glycosaminoglycans activate peptidylarginine deiminase 4 by enhancing calcium affinity

G Grzegorz P. Bereta (Malopolska Centre of Biotechnology, Jagiellonian University) E Ewa Bielecka K Karolina Marzec (Malopolska Centre of Biotechnology, Jagiellonian University) Łukasz Pijanowski (Malopolska Centre of Biotechnology, Jagiellonian University) A Artur P. Biela (Malopolska Centre of Biotechnology, Jagiellonian University) P Piotr Wilk (Malopolska Centre of Biotechnology, Jagiellonian University) M Marta Kamińska (Broegelmann Research Laboratory, University of Bergen) J Jakub Nowak E Elżbieta Wątor-Wilk (Malopolska Centre of Biotechnology, Jagiellonian University) P Przemysław Grudnik D Dominik Kowalczyk (Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University) J Joanna Kozieł (Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University) P Piotr Mydel (Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University) M Marcin Poręba (Department of Chemical Biology and Bioimaging, Faculty of Chemistry, Wroclaw University of Science and Technology) T Tomasz Kantyka

Abstract

Rheumatoid arthritis is a chronic inflammatory disease driven by abnormal protein modifications. These include citrullination of arginine residues by the calcium-activated enzyme peptidylarginine deiminase 4 (PAD4). However, calcium in body fluids may not fully activate PAD4, suggesting the potential involvement of other activators. In this study, we investigated the ability of glycosaminoglycans (a class of negatively charged polysaccharides) to modulate PAD4 activity. We found that model glycosaminoglycans bind to the enzyme with a nanomolar affinity, increase its calcium sensitivity, and require enzyme dimerization for activation. These effects depend on the size and negative charge of the glycosaminoglycan, and its various natural forms activate PAD4. Thus, our findings elucidate a mechanism by which common physiological compounds modulate PAD4 activity, potentially contributing to disease etiology.

Article Details

Volume / Issue Vol. 122, Issue 44
Published November 04, 2025
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (15)

G

Grzegorz P. Bereta

Malopolska Centre of Biotechnology, Jagiellonian University

E

Ewa Bielecka

K

Karolina Marzec

Malopolska Centre of Biotechnology, Jagiellonian University

Łukasz Pijanowski

Malopolska Centre of Biotechnology, Jagiellonian University

A

Artur P. Biela

Malopolska Centre of Biotechnology, Jagiellonian University

P

Piotr Wilk

Malopolska Centre of Biotechnology, Jagiellonian University

M

Marta Kamińska

Broegelmann Research Laboratory, University of Bergen

J

Jakub Nowak

E

Elżbieta Wątor-Wilk

Malopolska Centre of Biotechnology, Jagiellonian University

P

Przemysław Grudnik

D

Dominik Kowalczyk

Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University

J

Joanna Kozieł

Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University

P

Piotr Mydel

Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University

M

Marcin Poręba

Department of Chemical Biology and Bioimaging, Faculty of Chemistry, Wroclaw University of Science and Technology

T

Tomasz Kantyka