Physical Chemistry Seminar (Master Seminar): The role of hydroxyproline in proton transport across collagen structures
Anna Orieshyna, Jennifer L Puetzer, and Nadav Amdursky
The role of hydroxyproline in proton transport across collagen structures
Anna Orieshyna, Jennifer L Puetzer, and Nadav Amdursky1
Schulich Faculty of Chemistry, Technion – Israel Institute of Technology, Haifa 3200003, Israel
Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA 23220, USA
Collagen is one of the most studied proteins due to its fundamental role in creating fibrillar structures and supporting tissues in our bodies. Accordingly, collagen is also one of the most used proteins for making tissue-engineered scaffolds for various types of tissues. Considering the high abundance of hydroxyproline (Hyp) within collagen, we hypothesize here that the hydroxy group of Hyp can support proton transport (PT) across collagen. For this purpose, we explore here three different collagen-based hydrogels: the first is based on the self-assembly of natural collagen fibrils, the second and third are both based on covalently linking between collagen, one using a self-coupling method, and the other using an additional crosslinker. Following the formation and characterization of the hydrogel, we introduce here a 2-step reaction, involving 1) attaching methanesulfonyl to the -OH of Hyp, followed by 2) removing the oxidized methanesulfonyl, thus, we are reverting Hyp to Pro. Following the characterization of the reaction using X-ray photoelectron spectroscopy and Hyp quantification, we explore the PT at each step of the reaction using ac-bias impedance measurements. We show that adding the methanesulfonyl group enhances PT, while reverting Hyp to Pro significantly reduces PT efficiency (compared to the initial point) with different efficiencies for the various collagen-based hydrogels. The ability of collagen to support PT can assist in our understanding of collagen’s natural role. The capacity to modulate the conductivity across collagen is very important to any applicable use of collagen in regenerative medicine.