Insulin optical rotation

Fig. 13. The thermal transition of insulin at pH 3.6 from the native to the denatured form, as followed by optical rotation. (Schellman, 1958c.)...

Insulin, one of the few protmns able to remain native in strong acid, has been reduced with sine and hydrochloric acid (102). Parallel with the destruction of activity there was a drop in specific optical rotation [at] from — 70 to — 24 . The authors point out that cjrstine, on being reduced to C3rsteine, changes its [at] from — 224 to — 13 . Allen and Murlin (124) observed reverrible inactivation of insulin by tin and dilute acid. Th also clmmed similar results by merely exposing the hormone to commercial hydrogen. 

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