| 摘要 |
Rhombohedral cryst. insulin with four Zn structure was converted to rhombohedral crystals with a two Zn structure by holding it at room temp. to 45≦̸C in a <67% NaCl soln. at pH 5.0-5.8. Thus, cryst. procine insulin (450,000IU) contg. 0.5% Zn was dissolved in 400 ml 0.03N HCl; mixed with 15 ml 1% ZnCl2 in 0.03N HCl; diluted with HCl to 500 ml; mixed with 500 ml soln. contg. 70 g NaCl, 14 g NaOAc, and 10 ml 1N NaOH; and stirred at room temp. to give crystals with four Zn structure. The crystals were suspended. The X-ray spectrum showed complete conversion to the to Zn structure, which is more stable.
|
