Growth Hormone GMP quality

Growth hormone (GH), is a single polypeptide chain of 191 amino acids^[1](qv) having two disulfide bonds, one between Cys-53 and Cys-165, forming a large loop in the molecule, and the other between Cys-182 and Cys-189, forming a small loop near the C-terminus. The structure of GH is shown in Figure 1; molecular mass is 22,125; the empirical formula is C990H1529N262O300S7.

Purified GH is a white amorphous powder in its lyophilized form. It is readily soluble (concentrations>10 mg/mL) in dilute aqueous buffers at pH values above 7.2. The isoelectric point is 5.2 and the generally accepted value for the extinction coefficient at 280 nm is 17, 700 (M•cm)−1, although other values have been reported. The equilibrium denaturation of GH has been studied. A two-state mechanism is indicated with a Gibbs free energy of unfolding of 60.7 ± 4 kJ/mol (14.5 ± 1 kcal/mol).