| 摘要 |
<p>Conventional method of determining creatine phosphokinase (CPK) by reaction (A), the improvement comprising (novel feature; claimed) adding a sulphhydryl cpd. (II) in reduced form, and a buffer to maintain pH ca 9. (A) ATP + creatine ADP and phosphocreatine. (II) pref. glutathione in reduced form. Buffer pref. an Mg-tris buffer. Pref in modified test procedure, test soln. also contains phospho(enol) pyruvate and DPNH, when reactions (B) and (C) also occur. (B) ADP + phospho(enol) pyruvic acid ATP + Pyruvic acid (C) Pyruvic acid + beta -DPNH lactic acid + beta-DPN Concn. of DPNH is measured spectrophotometrically (at 340 m mu), and decrease in DPNH concn. may be related to activity of CPK in soln. (pref. measurements are also taken on a blank soln. (as above but omitting CPK)). It has been found that reaction rate becomes linear after a brief incubation period. In contrast with previous results, addition of (II) is reported to give a several fold increase in the reaction rate of (A), and also gives more reproducible results, thus affording a highly sensitive and reproducible method of determining CPK in sera (fresh and stored) etc. After incubation period, reaction rate is linear, and only 2 readings need to be taken (2nd 10 min. after 1st).</p> |
