Related Experiment Video
Updated: Jul 13, 2026

Sample Preparation in Quartz Crystal Microbalance Measurements of Protein Adsorption and Polymer Mechanics
Published on: January 22, 2020
Effect of salts on phase transition in native tendon collagen - an NMR study
1Department of Physics, Ben-Gurion University of the Negev, P.O.Box 653, 8410501, Beer-Sheva, Israel. pan@bgu.ac.il.
Objective:
This study aimed to investigate the effect of NaCl and KCl salts on the phase transition in native collagen.
Materials And Methods:
We studied native bovine tendons, which are 85% collagen, using solid-state NMR spectroscopy.
Results:
It was found that adding the above salts lowers the phase transition temperature, indicating that this parameter is highly sensitive to ionic species.
Discussion:
The observed phenomenon is explained by an increase in the rate of proton exchange (i) between water molecules and (ii) between water molecules and hydrogen atoms of collagen fibers, with which water forms hydrogen bonds. Accelerated exchange shortens the average lifetime of proton pairs and shifts the phase transition toward lower temperatures. Additional mechanisms that contribute to the averaging of local magnetic fields on the hydrogen nuclei of mobile water molecules are also discussed.
Related Concept Videos
¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
Phase Transitions: Melting and Freezing
