Abstract
The monomolecular character of the inactivation of pepsin by ultraviolet light has been demonstrated. 1 Recently, similar results 2 have been obtained with amylase, employing a viscosimetric method for estimations of concentration. As in the earlier work, infra-red radiation was absorbed in a filter of 5 mm. of water and it was demonstrated that the interposition of a No. 1 Crookes Glass filter prevented passage of the radiation responsible for the changes otherwise observable.
It seemed of interest to ascertain whether or not similar effects could be obtained with amylase in sera. A dilution of about 1 part of dog serum with 4 parts of 0.85% saline (containing 1.56 ± 0.02 units of amylase as estimated viscosimetrically) was irradiated for a period of 3 minutes at 10.0 ± 0.15°C. under conditions such that a simple 0.85% saline solution of pancreatin would have been about half inactivated, according to the findings of the previous work. 2 The estimated amylase concentration after irradiation was 1.52 ± 0.02 units—not significantly different from the previous value (the indicated dispersion measures being the A.D.). In a similar manner solutions containing serum from the same animal mixed in 0.85% saline with pancreatin solution (concentration of amylase, about 10 units) were irradiated with evidence of similar protection in the case of those containing 20% serum even when irradiated under the same conditions for 30 minutes. Finally, such a solution containing but 0.2% serum was about half inactivated in 6 minutes of such irradiation, about half the reaction speed of a similar solution without serum.
Other workers have observed protective effects upon enzymes in the irradiation of animals 3 with ultraviolet and other radiation from a mercury are in quartz.
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