An improved method for the determination of pantothenic acid in tissues.

During work on coenzyme A (CoA), a method for the liberation of pantothenic acid from the coenzyme was worked out (1). The method involves the use of a combination of two enzymes; namely, intestinal phosphatase and an enzyme extractable from acetone powder of bird liver (chicken (2), duck, or pigeon). This procedure proved the most efficient pretreatment to liberate bound vitamin under conditions in which takadiastase, papain, or mylase P, enzymes which are usually employed to release bound pantothenate, are unsuccessful. Neilands and Strong (2) have applied this method to the measurement of pantothenate in various biological products and were able to demonstrate a 4to lo-fold greater yield of pantothenate than by the use of the earlier methods for estimating boung pantothenate. A considerable inconvenience in the use of the combined enzyme method, already apparent in the earlier work (l), was the relatively high pantothenate blank introduced by the enzyme preparations, in particular the liver enzyme. This high blank necessitates applying a correction factor, which in the case of materials of low pantothenate content may represent up to about 100 per cent of the pantothenate present in the test material. This high enzyme blank is due to the relatively high CoA content in the liver enzyme, which, during the incubation period, is converted to pantothenate. Recently a method for reducing the CoA content of the liver enzyme has been developed, which is based on the observation, in this laboratory (3), that CoA can be very efficiently adsorbed by various resins as well as by charcoal. It appeared that by treatment with one of these resins the CoA content, and therewith the blank of the liver enzyme, can be reduced to a very low level without appreciable loss of CoA-splitting activity. The present report is a description of the application of resin treatment to the preparation of liver enzyme and its use in liberating bound pantothenate. Enzyme Preparations