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Identification of three amino acid residues in the B‐chain of platelet‐derived growth factor with different importance for binding to PDGF α‐ and β‐receptors
Author(s) -
Kreysing Joachim,
Östman Arne,
van de Poll Monique,
Bäckström Gudrun,
Heldin Carl-Henrik
Publication year - 1996
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(96)00349-3
Subject(s) - receptor , platelet derived growth factor receptor , biochemistry , amino acid , alanine , chemistry , biology , growth factor
The B‐chain homodimer isoform of platelet‐derived growth factor (PDGF) binds with high affinity both to α‐ and to β‐receptors. In order to localize amino acid residues in PDGFBB of differential importance for the binding to the two receptors, PDGF‐BB mutants were analyzed in which single amino acid residues were changed to alanine residues. We found that Phe‐118 in loop 1 of the PDGF B‐chain is crucial for binding to both receptors, and that the surrounding amino acids, Asn‐117 and Leu‐119, appear to be important primarily for binding to the β‐receptor. In contrast, Lys‐161 in loop 3 was found to be more important for binding to α‐receptors than β‐receptors. Previous studies have shown that the receptor binding epitope of PDGF‐BB is composed mainly of loops 1 and 3; the findings of the present study show that the α‐ and β‐receptors interact with different amino acid residues in these regions.