Evaluation of optimum in vitro for creatine kinase enzyme kinetic study of isolated from human sperm

Creatine kinase catalyzes the reversible transfer of a phosphoryl group from ATP to creatine, producing phosphocreatine (phosphagen). Phospho creatine as an energy source has an important role for sperm motility. Therefore, proper function of creatine kinase is the main factor of energy preparation for sperm movement. The aim of this study was to study the optimum in vitro creatine kinase enzyme kinetic after its isolation from human sperm.Subjects and Creatine kinase was extracted from approximately 30 ml human semen related to 10 health men with age average 30 ± 5 years, after washing, centrifuge and chromatography of sperms on DEAE-32 column. In each step of purification, protein levels and enzyme activity were assayed according to Bradford and Rosalki methods, respectively. Results this study showed that human sperm creatinine kinase activity increased by 67% with increase of the creatine phosphate concentration from 0.5 to 10 mM. Moreover pH change from 6 to 6.8 also showed an increase in the activity of this enzyme. Ceatine kinase activity increased in the temreure range of 20 to 40 °C. Our results showed that the most suitable substrate concentration, temperature and pH for optimum activity of human sperm creatine kinase were at 3 mM, 40°C and 6.8 respectively.