Identification of distinct C3b and C4b recognition sites in the human C3b/C4b receptor (CR1, CD35) by deletion mutagenesis.
نویسندگان
چکیده
منابع مشابه
Identification of distinct C3b and C4b recognition sites in the human C3b/C4b receptor (CR1, CD35) by deletion mutagenesis
Complementary DNA clones encoding the NH2-terminal region of human CR1 have been isolated and sequenced. The deduced complete amino acid sequence of the F allotype of human CR1 contains 2,039 residues, including a 41-residue signal peptide, an extracellular domain of 1,930 residues, a 25-amino acid transmembrane domain, and a 43-amino acid cytoplasmic region. The extracellular domain is compose...
متن کاملCharacteristics of isolated erythrocyte complement receptor type one (CR1, C4b-C3b receptor) and CR1-specific antibodies.
Complement receptor type one (CR1) was isolated from detergent-solubilized human erythrocyte (E) membranes by modification of a previously described technique. The isolated CR, was labeled with 1251 and was shown to be bound by either C4bor CSb-coated sheep E (EAC14b or ECBb), but not by sheep E coated with either C3bi or C3d (EC3bi or EC3d). When analyzed by sodium dodecyl sulfate polyacrylami...
متن کاملControl of the function of substrate-bound C4b-C3b by the complement receptor Cr1
The complement fragments C3b and C4b are the main ligands for the membrane receptor CR1. We showed elsewhere that CR1 functions as an essential cofactor for the factor I-mediated enzymatic breakdown of membrane-bound C3b (*C3b) into C3c and * C3dg . One of the main findings of the present paper is that CR1 also promotes the degradation of bound C4b (*C4b) into C4c and *C4d. On a weight basis, t...
متن کاملStructure of the C3b Binding Site of CR1 (CD35), the Immune Adherence Receptor
Complement receptor type 1 (CR1 or CD35) is a multiple modular protein that mediates the immune adherence phenomenon, a fundamental event for destroying microbes and initiating an immunological response. It fulfills this role through binding C3b/C4b-opsonized foreign antigens. The structure of the principal C3b/C4b binding site (residues 901-1095) of CR1 is reported, revealing three complement ...
متن کاملThe C4A and C4B isotypic forms of human complement fragment C4b have the same intrinsic affinity for complement receptor 1 (CR1/CD35).
Several previous reports concluded that the C4b fragment of human C4A (C4Ab) binds with higher affinity to CR1 than does C4Bb. Because the isotypic residues, (1101)PCPVLD and (1101)LSPVIH in C4A and C4B, respectively, are located within the C4d region, one may have expected a direct binding contribution of C4d to the interaction with CR1. However, using surface plasmon resonance as our analytic...
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ژورنال
عنوان ژورنال: Journal of Experimental Medicine
سال: 1988
ISSN: 0022-1007,1540-9538
DOI: 10.1084/jem.168.5.1699