Premium
The reaction of α‐crystallin with the cross‐linker 3,3′‐dithiobis(sulfosuccinimidyl propionate) demonstrates close proximity of the C termini of αA and αB in the native assembly
Author(s) -
Swaim Catherine L.,
Smith David L.,
Smith Jean B.
Publication year - 2004
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1110/ps.04910004
Subject(s) - crystallin , chemistry , chaperone (clinical) , lysine , propionate , linker , stereochemistry , protein structure , cross link , biochemistry , biophysics , crystallography , amino acid , biology , organic chemistry , medicine , polymer , computer science , operating system , pathology
The chaperone‐like activity of human lens α‐crystallin in inhibiting the aggregation of denatured proteins suggests a role for α‐crystallin in cataract prevention. Although a variety of techniques have generated structural information relevant to its chaperone‐like activity, the size and heterogeneity of α‐crystallin have prevented determination of its crystal structure. Even though synthetic cross‐linkers have provided considerable information about protein structures, they have not previously been used to study the proximity and orientation of subunits within human α‐crystallin. Cross‐linkers provide structural insight into proteins by binding the side chains of amino acids within close proximity. To identify the cross‐linked residues, the modified protein is digested and the resulting peptides are analyzed by mass spectrometry. Analysis of products from the reaction of α‐crystallin with 3,3′dithiobis(sulfosuccinimidyl propionate), DTSSP, identified several modifications to both αA and αB. The most structurally informative of these modifications was a cross‐link between lysine 166 of αA and lysine 175 of αB. This cross‐link provides experimental evidence supporting theoretical structural models that place the C termini of αA and αB within close proximity in the native aggregate.