Work

Probing the Role of Hydration in the Unfolding Transitions of Carbonmonoxy Myoglobin and Apomyoglobin

Year: 2009

Type: article

Abstract: We show that the equilibrium unfolding transition of horse carbonmonoxy myoglobin monitored by the stretching vibration of the CO ligand, a local environmental probe, is very sharp and, thus, quite different from those measured by global conformational reporters. In addition, the denatured protein exhibits an A(0)-like CO band. We hypothesize that this sharp transition reports penetration of water into the heme pocket of the protein. Parallel experiments on horse apomyoglobin, wherein an environment-sensitive fluorescent probe, nile red, was used, also reveals a similar putative hydration event. Given the importance of dehydration in protein folding and also the recent debate over the interpretation of probe-dependent unfolding transitions, these results have strong implications on the mechanism of protein folding.

Source: The Journal of Physical Chemistry B

DOI: 10.1021/jp900009x

Authors: Lin Guo, Jaeheung Park, Taegon Lee, Pramit Chowdhury, Manho Lim, Feng Gai

Institutions: Pusan National University, University of Pennsylvania

Language: English

Topic: Protein Structure and Dynamics

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: green