title: Evidence for the steric proximity of Tyr 174 and Lys 111 in bovine growth hormone.
abstract: Bovine growth hormone was modified by reaction with 1,5-difluoro-2,4-dinitrobenzene under conditions favouring production of intramolecularly crosslinked derivatives from monomeric molecules. The monomeric fraction, isolated by chromatography on Sephadex G-100, was oxidized or reduced and carbamidomethylated and trypsin digested. The resulting peptides were fractionated on SP-Sephadex and further purified by peptide mapping or HPLC. Two modified peptides containing sequences 108-112 or 108-113 and 171-176 of bGH were obtained, including a dinitrophenylene bridge between lysine 111 and tyrosine 174, thus suggesting the stereochemical proximity of these residues.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D004591:Electrophoresis, Polyacrylamide Gel; D013006:Growth Hormone / Q000032:analysis*; D006868:Hydrolysis; D008239:Lysine / Q000032:analysis*; D010084:Oxidation-Reduction; D010455:Peptides / Q000032:analysis; D011487:Protein Conformation; D014357:Trypsin; D014443:Tyrosine / Q000032:analysis*
chemical_list: D010455:Peptides; D014443:Tyrosine; D013006:Growth Hormone; D014357:Trypsin; D008239:Lysine