Significance of Km in Enzyme Kinetics, Michaelis-Menten Graph

University:
Swansea University
Course:
PM-133 | Evolutionary and Molecular Genetics
Academic year:

2023
Views:

173

Pages:

3
Author:

Amal J.

Significance of KM.(milor)Value of Kim = 10' to 107, if tim = 10' to [s] in required to balf fillthe active siteKM in an affinity indicator.KM = K2 + K-1K1K., higher than K2K-1 > > > K2kim = K-1 = Kd (dissacoriation constant).K1Kd=K-Iif K-1 in more backward reaction inK1more favoured, then enzyme in not goodKM / Kd should be low for a good enzymeVmax = K2 [ET]rate when velocity in maxTurn over no:No: of substrate molecules being converted to product pel unitenzyme per unit time.K2Kcat (turn over value or turn over constant for a kinetically perfect enzyme (convert all sobstrate encounteredinto product)for a kinetically perfect enzymeKcat = high.KmExampleSuperoxide dismutase (SOD)carbonic onhydraseTriose phosphate isomeraseMichaelis-Menter - Graph:exact Vmax value cannot befound from the M-M graphVmaxHense to obtain an exactVmax value the eqn inmodified.by takin reciprocal of M-MYoequation.[s]RecyrocalLine weaver-Burk Plot (LB plot)I = Kmt.[s]Vo Vmax[s]= Km + [STVmax [s] Vmax(s)I = km+Vo Vmax [s] Vmax.- 1 = Kin X 1 + IVoVmar [s] VmaxY = - m X t CLet Y=O is 1/vo = O1)1/Vmax= Kim X 1KimVmax Vmar [S]YVmax1 =[s] : [KM]xKM1X intercept = o[s]1==rcl