Santa H, Saarela J T, Laatikainen R, Rautianen J, Virtanen T, Rytkönen M, Mäntyjärvi R
Department of Chemistry, University of Kuopio, Finland.
J Protein Chem. 1998 Oct;17(7):657-62. doi: 10.1007/BF02780967.
The most important allergenic protein in cow dander and urine is Bos d 2. It is proposed to belong to the family of lipocalins, which are proteins capable of binding small hydrophobic molecules. The allergenic properties of Bos d 2 indicate an interaction between the accessible regions of the native protein and IgE. In this work, a three-dimensional model was created for Bos d 2 by comparative modeling, and features characteristic of outlier lipocalins were observed. The protruding regions of the surface were characterized and used in predicting the possible B-cell epitopes. There is a pocket inside the core and its size is appropriate for small molecules. The model shows a hydrophilic amino acid side chain of glutamic acid 115 on the inner surface of the hole and a phenylalanine as the "gatekeeper" instead of tyrosine, which is common in experimentally modeled lipocalins.