Analysis by site-directed mutagenesis of the possible role of tyrosine-13 of human EGF in receptor binding

Conference · Fri Mar 15 04:00:00 EST 1991 · FASEB Journal (Federation of American Societies for Experimental Biology); (United States)

OSTI ID:5242638

Tadaki, D K; Niyogi, S K ^[1]

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1. Oak Ridge National Lab., TN (United States)

Epidermal growth factor (EGF) is a polypeptide that plays an important role in the regulation of cell proliferation. The amino acid residue at position {number sign}13 of EGF is conserved as either a tyrosine of phenylalanine in several species of EGF and transforming growth factor alpha (TGF-{alpha}), whose biological actions are initiated by interaction with the EGF receptor. From NMR data, the residue at position 13 is one of the residues presumed to be on the face of the ligand involved in its interaction with the receptor. Site-directed mutagenesis was employed to create single amino acid substitutions at the tyrosine-13 site. These mutants were tested by radio receptor competition binding assay and by a tyrosine kinase stimulation assay for activity as compared to wild type human EGF (hEGF). A conservative substitution such as Tyr13{yields}Phe resulted in an hEGF analog retaining activity very close to wild type, while nonconservative substitutions like Tyr 13{yields}Ala or Tyr13{yields}Gly resulted in hEGF mutants having activities of 3% and 0.3% of wild type, respectively. Interestingly, replacement of the aromatic residue with a hydrophobic residue, namely leucine, produced an hEGF analog with an activity 80% that of wild type. Previous studies from this laboratory have implicated the importance of several hydrophobic residues in the hEGF molecule in its binding to the receptor.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5242638
• Report Number(s): CONF-9104107--
• Conference Information: Journal Name: FASEB Journal (Federation of American Societies for Experimental Biology); (United States) Journal Volume: 5:5
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANIMAL TISSUES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL FUNCTIONS
BODY
CARBOXYLIC ACIDS
EPIDERMIS
EPITHELIUM
GROWTH FACTORS
HYDROXY ACIDS
ISOTOPE APPLICATIONS
KINETICS
MEMBRANE PROTEINS
MITOGENS
MUTAGENESIS
NMR SPECTRA
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RADIORECEPTOR ASSAY
REACTION KINETICS
RECEPTORS
SKIN
SPECTRA
STRUCTURE-ACTIVITY RELATIONSHIPS
TISSUES
TRACER TECHNIQUES
TYROSINE