Structural characterization of a recombinant CD4-IgG hybrid molecule.
CD4-IgG is a homodimer of a hybrid polypeptide consisting of the two amino-terminal domains (residues 1-180) of human CD4 fused to the hinge region and the second and third constant-sequence (CH2 and CH3) Fc domains (residues 216-441) of human immunoglobulin G (IgG-1). This antibody-like molecule, termed an immunoadhesin, was produced in an effort to combine the binding specificity of CD4 with several potentially desirable properties of IgG molecules [Capon et al. (1989) Nature 337, 525-531]. The structural characteristics of the molecule have been evaluated to demonstrate that CD4-IgG has the same features as the N-terminal region of soluble CD4, while retaining those expected for the Fc portion of human IgG. Identification of peptides recovered from the tryptic map confirmed 98.8% of the expected structure of CD4-IgG. The detection of glucosamine in peptides containing Asn257 and the retention time shift of this tryptic peptide after deglycosylation confirmed the presence of Asn-linked oligosaccharides at this position. Four pairs of intrachain and two interchain disulfide bonds were also established.
Harris
R J
RJ
Department of Medicinal and Analytical Chemistry, Genentech, Inc., South San Francisco, CA 94080.
Wagner
K L
KL
Spellman
M W
MW
D000595:Amino Acid Sequence; D000818:Animals; D015704:CD4 Antigens / Q000235:genetics*; D002851:Chromatography, High Pressure Liquid; D006224:Cricetinae; D003412:Cricetulus; D006801:Humans; D007074:Immunoglobulin G / Q000235:genetics*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010449:Peptide Mapping; D013438:Sulfhydryl Compounds; D014357:Trypsin
D015704:CD4 Antigens; D007074:Immunoglobulin G; D013438:Sulfhydryl Compounds; D014357:Trypsin