Michaelis constant

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Mi·chae·lis con·stant

(mi-kā'lis),
1. the true dissociation constant for the enzyme-substrate binary complex in a single-substrate rapid equilibrium enzyme-catalyzed reaction (usually symbolized by Ks);
2. the concentration of the substrate at which half the true maximum velocity of an enzyme-catalyzed reaction is achieved (when velocities are measured under initial rate and steady-state conditions); the ratio of rate constants (k2 + k3)/k1 in the single-substrate enzyme-catalyzed reaction: E + S ⇄ ES ⇄ E + products, where E represents the free enzyme, S is the substrate, and ES is the central binary complex. The expression for the Michaelis constant will be more complex for multisubstrate reactions. An apparent Michaelis constant is a constant determined either under conditions that are not strictly steady-state and initial rate or under a condition that varies with the concentration of one or more cosubstrates.
[Leonor Michaelis]

Mi·chae·lis con·stant

(mi-kā'lis kon'stănt)
1. The true dissociation constant for the enzyme-substrate binary complex in a single-substrate rapid equilibrium enzyme-catalyzed reaction (usually symbolized by Ks).
2. The concentration of the substrate at which half the true maximum velocity of an enzyme-catalyzed reaction is achieved.
[Leonor Michaelis]

Michaelis,

Leonor, German-U.S. chemist and physician, 1875-1949.
Michaelis buffer
Michaelis constant - the true dissociation constant for the enzyme-substrate binary complex in a single-substrate rapid equilibrium enzyme-catalyzed reaction. Synonym(s): Michaelis-Menten constant
Michaelis-Gutmann body - a rounded homogenous body containing calcium and iron found within macrophages in the bladder wall in malacoplakia.
Michaelis-Menten constant - Synonym(s): Michaelis constant
Michaelis-Menten equation - an initial-rate equation for a single-substrate noncooperative enzyme-catalyzed reaction relating the initial velocity to the initial substrate concentration. Synonym(s): Victor-Michaelis-Menten equation
Michaelis-Menten hypothesis - that a complex is formed between an enzyme and its substrate (the O'Sullivan-Tompson hypothesis), which complex then decomposes to yield free enzyme and the reaction products (Brown hypothesis), the latter rate determining the overall rate of substrate-product conversion.
Victor-Michaelis-Menten equation - Synonym(s): Michaelis-Menten equation
References in periodicals archive ?
Y' = 1 / 2b into equation 2 to find x, and the value of Y obtained from equation 1 is Km (the Michaelis-Menten constant, which is the concentration of ions in the solution at half of the maximum rate of the absorbed ions).
The data obtained from Lineweaver Burk plot suggested that Michaelis-Menten constant was increased while maximum reaction rate was decreased as a result of immobilization (Table 2).
Further, the Michaelis-Menten constant increased lightly, which indicates a mixed inhibition mechanism [30, 31].
The apparent Michaelis-Menten constant ([K.sub.M.sup.app]) was calculated from the corresponding Lineweaver-Burk plots (Fig.
The Michaelis-Menten constant ([K.sub.m]) and maximum velocity ([V.sub.max]) values were determined from Lineweaver-Burk plots.
The ratio of the Michaelis-Menten constants allowed the calculation of the catalytic efficiency of the enzymes.
Kinetics assays were carried out to determine Michaelis-Menten constants.
where [J.sup.+.sub.i] and [J.sup.-.sub.i] are the total fluxes of production and elimination of [n.sub.i] and they are determined by Michaelis-Menten constants and i = A, B, C.
Michaelis-Menten constants ([K.sub.m]) and maximum formation rates ([V.sub.max]) were determined by Lineweaver-Burk plot analysis.
The Michaelis-Menten constants of free and immobilized quince leaf PPO were calculated by using Lineweaver-Burk double reciprocal models [14].
DETERMINATION OF MICHAELIS-MENTEN CONSTANTS ([K.sub.M]) FOR XYLOSYLATION OF DIFFERENT ACCEPTORS