Juvenile hormone carrier protein of Manduca sexta haemolymph. Improved purification procedure; protein modification studies and sequence of the amino terminus of the protein
التفاصيل البيبلوغرافية
العنوان:
Juvenile hormone carrier protein of Manduca sexta haemolymph. Improved purification procedure; protein modification studies and sequence of the amino terminus of the protein
A procedure is described for purification of the juvenile hormone carrier protein from the last larval instar of Manduca sexta. Homogeneous carrier protein is obtained after three chromatographic steps in up to 36% yield, based upon the recovery from the first gel permeation chromatography step. The sequence of the N- terminus of the polypeptide chain was determined for 19 of the first 20 residues: l 10 Asp-Gln-Gly-Ala-Leu-Phe-Glu-Pro-Cys-Ser- 11 20 Thr-GIn-Asp-lle-Ala-Cys-Leu-Ser- ?-Ala- Three reagents which modify side chain residues in proteins: methyl acetimidate (amino groups), N- succinimidyl -3-(4- hydroxyphenyl ) propionate (amino groups) and tetranitromethane (phenol groups), were reacted with pure carrier protein. In each case, there was relatively little change in the juvenile hormone binding properties of the modified carrier protein.