This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Brownsey, G. J. Articles by Ring, S. G. Search for Related Content PubMed PubMed Citation Articles by Brownsey, G. J. Articles by Ring, S. G.

The Glass Transition Behavior of the Globular Protein Bovine Serum Albumin

Institute of Food Research, Norwich Research Park, Colney, Norwich, NR4 7UA, United Kingdom

Correspondence: Address reprint requests to Dr. Steve G. Ring, Institute of Food Research, Norwich Research Park, Colney Lane, Norwich, NR4 7UA, UK. Tel.: +44-(0)1603-255031; Fax: +44-(0)1603-507723; E-mail: steve.ring{at}bbsrc.ac.uk.

The glass-like transition behavior of concentrated aqueous solutions of bovine serum albumin was examined using rheological techniques. At mass fractions >0.4, there was a marked concentration dependence of viscosity with a glass-like kinetic arrest observed at mass fractions in the region of 0.55. At mass fractions >0.6 the material behaved as a solid with a Young's modulus rising from 20 MPa at a mass fraction of 0.62–1.1 GPa at 0.86. The solid was viscoelastic and exhibited stress relaxation with relaxation times increasing from 33 to 610 s over the same concentration range. The concentration dependence of the osmotic pressure was measured, at intermediate concentrations, using an osmotic stress technique and could be described using a hard sphere model, indicating that the intermolecular interactions were predominantly repulsive. In summary, a major structural relaxation results from the collective motion of the globules at the supra-globule length scale and, at 20°C, this is arrested at water contents of 40% w/w. This appears to be analogous to the glass transition in colloidal hard spheres.

This article has been cited by other articles:

				R. Parker, T. R. Noel, G. J. Brownsey, K. Laos, and S. G. Ring The Nonequilibrium Phase and Glass Transition Behavior of {beta}-Lactoglobulin Biophys. J., August 1, 2005; 89(2): 1227 - 1236. [Abstract] [Full Text] [PDF]