Michales-Menten equation derived using the standard quasi steady-state approximation (sQSSA) has been widely used for the estimation of enzyme kinetic parameters. However, such approximation is only valid when enzyme concentrations is low. Thus, we found that the estimation can be biased when enzyme concentration is high. On the other hand, we found that a newly reduced model using the total QSSA (tQSSA) provides the accurate estimation of parameters regardless of enzyme concentration. For the estimation of parameters, we utilized the Markov Chain Monte Carlo (MCMC) based on the Bayesian approach to estimate parameter using non-informative and informative priors.