Enzymes [antikvár]

Since the last edition of this booklet, the biochemical program "Enzymes for biochemistry" has been enlarged by a number of additional substances. Of special interest may be a line of polymerically bound enzymes, whose insol-uble carriers are either CM-cellulose or a special cross-linked maleic anhy-dride which was developed in our laboratories. Somé natural inhibitors complete the rangé of new products. The brochure contains the most important informations on the individual products, like the test conditions, and the definition of the units in which the declared enzymatic activities are expressed. The given values are guaran-teed minimum activities which the enzymes have when they leave the factory. The activity is expressed - as far as sensible - according to the definition of the Commission on Enzymes ("Report of the Commission on Enzymes of the International Union of Biochemistry", Pergamon Press, Oxford 1961): One Unit (U) corresponds to: Turnover of 1 [imole of substrate per minute under optimum conditions. If for cogent reasons, optimum conditions are not applicable (e. g. because of limited solubility of the substrate) those conditions nearest the optimum are chosen. More comprehensive descriptions of the assay methods are available on request. The necessary substrates are specified in our booklet "Enzyme Substrates". In those cases where hemoglobin is used as a substrate, the activity is given in Anson units. The units PUK in the case of pro-nase E and PU in the case of thermolysin are in agreement with the activity definitions of the Japanese authors. The addition "cryst." means that repeated crystallisations have been carried out as purification steps until optimum purity has been attained, revealed by the constancy of the activity, or by the uniformity of the protein shown by the disc electrophoresis. The lyophilised preparations are practically free of salts. A generál description gives information on the condition and the origin of the product, further on the reaction catalysed by the enzyme. The systematic name and the system number given are in accordance with the recommen-dations of the Commission on Enzymes. Data on other commonly used activity definitions, known secondary activities, stability limits, important literature references, and in somé cases suggestions for application complete the specifications of the products. It is recommended to store the enzymes at the temperatures indicated in the specifications under "Stability".