The Catabolism of I-131-insulin by Rat Lens Homogenates.
نویسندگان
چکیده
The ability of a rat lens homogenate to degrade radioiodinated zinc insulin into fractions which now are TCA soluble was used as a criterion of proteolysis. The assay method is extremely simple, rapid, and sensitive. Proteolytic activity is linearly related to the amount of lens homogenate added. The lens enzyme has a pH optimum of approximately 7.2, a temperature maximum near 50° C, and is inactivated by sulfhydryl inhibitors and heavy metals. Almost all of the enzyme activity is found in the water soltible fraction of the lens. Addition of crystalline zinc insulin competitively inhibits the breakdoton of the I-131-insulin. This enzyme system or another enzyme exhibits a pH optimum above pH 10, a temperature maximum near 50° C, and has rather unique reaction kinetics.
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عنوان ژورنال:
- Investigative ophthalmology
دوره 2 شماره
صفحات -
تاریخ انتشار 1963