isozyme

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isoenzyme

 [i″so-en´zīm]
any of several forms of an enzyme that all catalyze the same reaction but may differ in reaction rate, inhibition by various substances, electrophoretic mobility, or immunologic properties. Several enzymes, particularly alkaline phosphatase, lactate dehydrogenase, and creatine kinase, have clinically important isoenzymes. Isoenzymes are separated by electrophoresis, and the pattern indicates which damaged organ has released the enzymes.

i·so·en·zyme

(ī'sō-en'zīm),
An enzyme (one of a group) that catalyze the same reaction but may be differentiated by variations in physical properties, such as isoelectric point, electrophoretic mobility, kinetic parameters, or modes of regulation, for example, lactate dehydrogenase, a tetramer composed of varying amounts of α and β subunits (that is, 4α, 3α + 1β, 2α + 2β, 1α + 3β, and 4β).
Synonym(s): isozyme

isozyme

(ī′sə-zīm′)
n.
An isoenzyme.

i′so·zy′mic adj.

i·so·en·zyme

(ī'sō-en'zīm)
One of a group of enzymes that catalyze the same reaction but may be differentiated by variations in physical properties, such as isoelectric point, electrophoretic mobility, kinetic parameters, or modes of regulation.

isozyme

see ISOENZYME.
References in periodicals archive ?
Christianson, X-ray crystallographic studies of mammalian carbonic anhydrase isozymes, Carb.
Isoenzymes expression: The induction of new isozymes and the change in the isoenzymes profiles play an important role in the cellular defense against oxidative stress.
With the exception of residue 67, the majority of residues in the 5 - 10 A zone remain conserved between the isozymes. This observation is reinforced by the lack of selectivity observed for compact CAIs that bind deep within the active site.
Histidine, phenylalanine, sildenafil citrate have been shown to be potential activators of different CA isozymes. D-3,4-dihydroxyphenylalanine; dextrodopa (D-DOPA), L-Tyr, and 4-amino-L-Phe act as perfect activators for CAs like the histamine.
The highest enzymatic activity was belonged to tolerant group under severe stress conditions for almost all of isozymes reported.
Gamma rays and JA treatments caused changes in activities, the band concentration of peroxidase and polyphenol oxidase isozymes and increase amino acid contents.
The predominance of U-LDH1 and U-LDH2 isozymes in the acute phase of KD is thought to be derived from the kidney and urinary tract.
We then investigated the involvement of CYPs in the metabolism of LDT5, using the human CYP1A2, 2C9, 2C19, 2D6 and 3A4 isozymes. To summarize our results (Table 2), LDT5 was found to be a substrate of CYP2D6 with a half-life of 5 min and CYP2C19 with a half-life of 20 min.
We used isozymes, plastid, and nuclear DNA sequences of samples collected within the three species' natural ranges to answer these questions.
Almost all types of molecular markers have been tested in chickpea including isozymes (7,15), restriction fragment length polymorphism (RFLP) (44), random amplified polymorphic DNA markers (RAPDs) (12), amplified fragment length polymorphisms (AFLPs) (28), sequence characterized amplified regions (SCARs) (19), inter-simple sequence repeat (ISSRs) (12), simple sequence repeat (STMS or SSR) (18,29), resistance gene analogs (RGAs)10, DNA amplification fingerprinting (DAF) (2) and expressed sequence tags (ESTs) (31).
Drug-metabolizing enzymes include many cytochrome P450 isozymes and others.