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Expression, crystallization, and preliminary X‐ray analysis of a sialic acid‐binding fragment of sialoadhesin in the presence and absence of ligand
Author(s) -
May A. P.,
Robinson R. C.,
Aplin R. T.,
Bradfield P.,
Crocker P. R.,
Jones E. Y.
Publication year - 1997
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 - 10.1002/pro.5560060321
Subject(s) - chinese hamster ovary cell , sialic acid , ligand (biochemistry) , immunoglobulin domain , chemistry , stereochemistry , antibody , siglec , crystallography , receptor , biology , biochemistry , immunology
Sialoadhesin is a macrophage‐restricted cell surface receptor, consisting of 17 immunoglobulin domains, which mediates cell adhesion via the recognition of specific sialylated glycocon‐jugates. A functional fragment of sialoadhesin, comprising the N‐terminal immunoglobulin domain, has been expressed in Chinese hamster ovary cells as both native (SnD 1) and selenomethi‐onyl (Se‐SnDl) stop protein. The successful production of 86% selenomethionine‐incorporated protein represents a rare example of production of selenium‐labeled protein in mammalian cells. SnDl and Se‐SnDl have been crystallized in the absence of ligand, and SnDl has also been crystallized in the presence of its ligand 2,3 sialyllactose. The ligand‐free crystals of SnDl and Se‐SnDl were isomorphous, of space group P3t2\ or P3221, with unit cell dimensions a = b = 38.9 A, c = 152.6 k,a = (3 = 90°, y = 120°, and diffracted to a maximum resolution of 2.6 A. Cocrystals containing 2,3 sialyllactose diffracted to 1.85 A at a synchrotron source and belong to space group P21212, with unit cell dimensions a = 40.9 A, b = 97.6 A, c = 101.6 A, a = /3 = y = 90°.