Surface interactions of gamma-crystallins in the crystal medium in relation to their association in the eye lens.
A comparative study of intermolecular interactions in crystals of two homologous low molecular weight proteins, gamma-II and gamma-IIIb crystallins, from calf eye lens was carried out. Crystal packings for these proteins are very different: intermolecular contact areas compose about 33% of the total accessible surface area of gamma-II as compared with 13% in gamma-III. Two key residues seem to be mainly responsible for the differences in protein association in the crystal medium. These are Ser 103 and Leu 155 in gamma-II, which are replaced by Met 103 and His 155 in gamma-IIb. A similar substitution of these residues is observed in different gene products of gamma-crystallins from a number of vertebrates. This is consistent with the existence of a genetically controlled mechanism for determining intermolecular association of gamma-crystallins in the native medium of the lens.
Sergeev
Y V
YV
Institute of Protein Research, Academy of Sciences of the USSR, Pushchino, Moscow Region.
Chirgadze
Y N
YN
Mylvaganam
S E
SE
Driessen
H
H
Slingsby
C
C
Blundell
T L
TL
D000595:Amino Acid Sequence; D000818:Animals; D003459:Crystallins / Q000235:genetics / Q000378:metabolism*; D003460:Crystallization; D006801:Humans; D007908:Lens, Crystalline / Q000502:physiology*; D011487:Protein Conformation; D013045:Species Specificity; D013499:Surface Properties; D014961:X-Ray Diffraction
D003459:Crystallins