Oxidation of methionine residues in equine growth hormone by Chloramine-T.
1. Reactivity of methionine residues towards Chloramine-T was studied in the equine growth hormone. 2. With a 20.0-fold molar excess of reagent over methionine, full oxidation of the four residues of the protein is achieved. 3. Methionine 4 is the most reactive group, followed by methionines 72 and 178--methionine 123 being the less reactive residue. 4. As judged by circular dichroism spectra and binding assays, protein conformation and binding capacity to specific receptors remains unchanged even after full oxidation of all four methionine residues. 5. Results agree with data previously obtained with bovine growth hormone.
Mihajlovic
V
V
Instituto de Química y Fisicoquímica Biológicas (UBA-CONICET), Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina.
Cascone
O
O
Biscoglio de Jiménez Bonino
M J
MJ
D000595:Amino Acid Sequence; D000818:Animals; D002700:Chloramines / Q000494:pharmacology*; D013006:Growth Hormone / Q000378:metabolism*; D006736:Horses / Q000378:metabolism*; D008715:Methionine / Q000378:metabolism*; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D011485:Protein Binding; D014105:Tosyl Compounds / Q000494:pharmacology*
D002700:Chloramines; D014105:Tosyl Compounds; C016300:chloramine-T; D013006:Growth Hormone; D008715:Methionine