1 research outputs found
Nuclear Magnetic Resonance Structure of a Major Lens Protein, Human γC-Crystallin: Role of the Dipole Moment in Protein Solubility
A hallmark
of the crystallin proteins is their exceptionally high
solubility, which is vital for maintaining the high refractive index
of the eye lens. Human γC-crystallin is a major γ-crystallin
whose mutant forms are associated with congenital cataracts but whose
three-dimensional structure is not known. An earlier study of a homology
model concluded that human γC-crystallin has low intrinsic solubility,
mainly because of the atypical magnitude and fluctuations of its dipole
moment. On the contrary, the high-resolution tertiary structure of
human γC-crystallin determined here shows unequivocally that
it is a highly soluble, monomeric molecule in solution. Notable differences
between the orientations and interactions of several side chains are
observed upon comparison to those in the model. No evidence of the
pivotal role ascribed to the effect of dipole moment on protein solubility
was found. The nuclear magnetic resonance structure should facilitate
a comprehensive understanding of the deleterious effects of cataract-associated
mutations in human γC-crystallin