Circular dichroism and site-directed spin labeling reveal structural and dynamical features of high-pressure states of myoglobin.

ABSTRACT: Excited states of proteins may play important roles in function, yet are difficult to study spectroscopically because of their sparse population. High hydrostatic pressure increases the equilibrium population of excited states, enabling their characterization [Akasaka K (2003) Biochemistry 42:10875-85]. High-pressure site-directed spin-labeling EPR (SDSL-EPR) was developed recently to map the site-specific structure and dynamics of excited states populated by pressure. To monitor global secondary structure content by circular dichroism (CD) at high pressure, a modified optical cell using a custom MgF2 window with a reduced aperture is introduced. Here, a combination of SDSL-EPR and CD is used to map reversible structural transitions in holomyoglobin and apomyoglobin (apoMb) as a function o

SUBMITTER: Lerch MT 

PROVIDER: S-EPMC3856799 | biostudies-literature | 2013 Dec

REPOSITORIES: biostudies-literature