Three-Dimensional Molecular Modeling of Bovine Caseins: αs1-Casein

Abstract

Structures derived from X-ray crystallography are extremely important in elucidating functional relationships for many proteins. However, the caseins of bovine milk are one class of noncrystallizable proteins. The complete primary and partial secondary structures of these proteins are known, but homologous proteins of known crystallographic structure cannot be found. Therefore, sequence-based predictions of secondary structure were made and adjusted to conform with global secondary structures determined by Raman spectroscopy. With this information, a three-dimensional structure for αs1-casein was constructed using molecular modeling programs. The predicted structure of αs1-casein contains a hydrophobic and a hydrophilic domain, which are connected by a segment of α-helix. This unrefined structure shows good agreement with global biochemical and chemical information concerning αs1-caseins A, B, and C. © 1991, American Dairy Science Association. All rights reserved.