WordNet

not involving competition or competitiveness; "noncompetitive positions"; "noncompetitive interest in games"
in a noncompetitive manner; "the scholarships will be awarded noncompetitively"
used to express refusal or denial or disagreement etc or especially to emphasize a negative statement; "no, you are wrong"
a negative; "his no was loud and clear"
referring to the degree to which a certain quality is present; "he was no heavier than a child" (同)no more
not in any degree or manner; not at all; "he is no better today"
quantifier; used with either mass nouns or plural count nouns for indicating a complete or almost complete lack or zero quantity of; "we have no bananas"; "no eggs left and no money to buy any"; "have you no decency?"; "did it with no help"; "Ill get you there in no time"
showing a fighting disposition; "highly competitive sales representative"; "militant in fighting for better wages for workers"; "his self-assertive and ubiquitous energy" (同)militant
involving competition or competitiveness; "competitive games"; "to improve ones competitive position" (同)competitory
subscribing to capitalistic competition (同)free-enterprise, private-enterprise
the fifth of the seven canonical hours; about 3 p.m.

PrepTutorEJDIC

《名詞の前に置いて》『一つも』(『一人も,少しも』)・・・『ない』 / 《補語につけて》『決して・・・でない』 / 《省略文で》・・・なし;・・・お断り / 《話》少ししか(あまり)・・・ない / (肯定の問いに対して)『いいえ』;(否定の問いに対して)はい,ええ / 《not, norの前に挿入して》『いや』,否 / 《形容詞の前に置その形容詞を否定して》…どころではない / 《比較級の前に置いて》ちっとも…でない,…と全く同じ / 《… or no の形で》…であってもなくても / 《驚き・困惑・不信などを表して》とんでもない / 《単数形で》『拒否』,「『いいえ』」という返事 / 《複数形で》反対[投]票
競争の,競争による

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/09/18 14:21:57」(JST)

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[Wiki en表示]

Non-competitive inhibition is a type of enzyme inhibition where the inhibitor reduces the activity of the enzyme and binds equally well to the enzyme whether or not it has already bound the substrate.^[1]

If the inhibitor may bind to the enzyme whether or not the substrate has already been bound, but has a higher affinity for binding the enzyme in one state or the other, it is called a mixed inhibitor.^[1]

Terminology

It is important to note that while all non-competitive inhibitors bind the enzyme at allosteric sites (i.e. locations other than its active site)—not all inhibitors that bind at allosteric sites are non-competitive inhibitors.^[1]^[2] In fact, allosteric inhibitors may act as competitive, non-competitive, or uncompetitive inhibitors.^[1]

Many sources continue to conflate these two terms,^[3]^[4] or state the definition of allosteric inhibition as the definition for non-competitive inhibition.

Mechanism

Illustration of a possible mechanism of non-competitive or mixed inhibition.

Non-competitive inhibition models a system where the inhibitor and the substrate may both be bound to the enzyme at any given time. When both the substrate and the inhibitor are bound, the enzyme-substrate-inhibitor complex cannot form product and can only be converted back to the enzyme-substrate complex or the enzyme-inhibitor complex. Non-competitive inhibition is distinguished from general mixed inhibition in that the inhibitor has an equal affinity for the enzyme and the enzyme-substrate complex.

The most common mechanism of non-competitive inhibition involves reversible binding of the inhibitor to an allosteric site, but it is possible for the inhibitor to operate via other means including direct binding to the active site. It differs from competitive inhibition in that the binding of the inhibitor does not prevent binding of substrate, and vice versa, it simply prevents product formation for a limited time.

This type of inhibition reduces the maximum rate of a chemical reaction without changing the apparent binding affinity of the catalyst for the substrate (K_m^app – see Michaelis-Menten kinetics).

Equation

In the presence of a non-competitive inhibitor, the apparent enzyme affinity is equivalent to the actual affinity. In terms of Michaelis-Menten kinetics, K_m^app = K_m. This can be seen as a consequence of Le Chatelier's Principle because the inhibitor binds to both the enzyme and the enzyme-substrate complex equally so that the equilibrium is maintained. However, since some enzyme is always inhibited from converting the substrate to product, the effective enzyme concentration is lowered.

Mathematically,

Example: noncompetitive inhibitors of CYP2C9 enzyme

Noncompetitive inhibitors of CYP2C9 enzyme include nifedipine, tranylcypromine, phenethyl isothiocyanate, and 6-hydroxyflavone. Computer docking simulation and constructed mutants substituted indicate that the noncompetitive binding site of 6-hydroxyflavone is the reported allosteric binding site of CYP2C9 enzyme.^[5]

References

^ ^a ^b ^c ^d "Types of Inhibition". Retrieved 2 April 2012.
^ "Non Competitive Inhibitors".
^ "Noncompetitive inhibition and allosteric inhibition". Biology Online (forum). Retrieved 2 April 2012.
^ "Noncompetitive Inhibition". Retrieved 2 April 2012.
^ Si Dayong, Wang Y, Guo Y, Wang J, Zhou H, Zhou Y-H, Li Z-S, Fawcett JP (2008). Mechanism of CYP2C9 inhibition by flavones and flavonols. Drug Metabolism and Disposition. doi:10.1124/dmd.108.023416 [1]

Berg, Jeremy M.; Tymoczko, John L.; Stryer, Lubert (2000), Biochemistry (5th ed.), New York: WH Freeman & Co., ISBN 0-7167-6766-X

UpToDate Contents

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English Journal

Ketamine administration during the second postnatal week induces enduring schizophrenia-like behavioral symptoms and reduces parvalbumin expression in the medial prefrontal cortex of adult mice.

Jeevakumar V1, Driskill C1, Paine A1, Sobhanian M1, Vakil H1, Morris B1, Ramos J1, Kroener S2.
Behavioural brain research.Behav Brain Res.2015 Apr 1;282:165-75. doi: 10.1016/j.bbr.2015.01.010. Epub 2015 Jan 13.
Dysfunctions in the GABAergic system are considered a core feature of schizophrenia. Pharmacological blockade of NMDA receptors (NMDAR), or their genetic ablation in parvalbumin (PV)-expressing GABAergic interneurons can induce schizophrenia-like behavior in animals. NMDAR-mediated currents shape th
PMID 25591475

Prolonged exposure of mixed aerobic cultures to low temperature and benzalkonium chloride affect the rate and extent of nitrification.

Yang J1, Tezel U1, Li K1, Pavlostathis SG2.
Bioresource technology.Bioresour Technol.2015 Mar;179:193-201. doi: 10.1016/j.biortech.2014.12.030. Epub 2014 Dec 16.
The combined effect of benzalkonium chloride (BAC) and prolonged exposure to low temperature on nitrification was investigated. Ammonia oxidation at 22-24°C by an enriched nitrifying culture was inhibited at increasing BAC concentrations and ceased at 15mg BAC/L. The non-competitive inhibition coef
PMID 25544497

Nine novel angiotensin I-converting enzyme (ACE) inhibitory peptides from cuttlefish (Sepia officinalis) muscle protein hydrolysates and antihypertensive effect of the potent active peptide in spontaneously hypertensive rats.

Balti R1, Bougatef A2, Sila A3, Guillochon D3, Dhulster P3, Nedjar-Arroume N3.
Food chemistry.Food Chem.2015 Mar 1;170:519-25. doi: 10.1016/j.foodchem.2013.03.091. Epub 2013 Apr 12.
This study aimed to identify novel ACE inhibitory peptides from the muscle of cuttlefish. Proteins were hydrolyzed and the hydrolysates were then subjected to various types of chromatography to isolate the active peptides. Nine ACE inhibitory peptides were isolated and their molecular masses and ami
PMID 25306378

Japanese Journal

Inhibitory kinetics of DABT and DABPT as novel tyrosinase inhibitors(ENZYMOLOGY, PROTEIN ENGINEERING, AND ENZYME TECHNOLOGY)

Yang Mei-Hua,Chen Chin-Min,Hu Yong-Hua,Zheng Cheng-Yi,Li Zhi-Cong,Ni Lian-Lian,Sun Li,Chen Qing-Xi
Journal of bioscience and bioengineering 115(5), 514-517, 2013-05
… = 6.49 μM, while that of DABPT displays non-competitive with the inhibition constant K_I = 0.77 μM. …
NAID 110009611454

Tyrosinase Inhibitory Effects and Antioxidant Properties of Paeonol and Its Analogues

ZHU Tian-Hua,YU Yan-Ying,CAO Shu-Wen
Food Science and Technology Research 19(4), 609-615, 2013
… The inhibition kinetics revealed that paeonol (a) was a mixed-type inhibitor, 2′-hydroxy acetophenone (c), 4′-hydroxy acetophenone (d), and 2,4′-dihydroxy acetophenone (e) were competitive inhibitors, while acetophenone (b), 2′-methoxyacetophenone (f), and 4′-methoxy acetophenone (g) behaved as non-competitive inhibitors. …
NAID 130003365287

Pentazocine Inhibits Norepinephrine Transporter Function by Reducing its Surface Expression in Bovine Adrenal Medullary Cells

Obara Go,Toyohira Yumiko,Inagaki Hirohide,Takahashi Keita,Horishita Takafumi,Kawasaki Takashi,Ueno Susumu,Tsutsui Masato,Sata Takeyoshi,Yanagihara Nobuyuki
Journal of Pharmacological Sciences 121(2), 138-147, 2013
… (±)-Pentazocine (PTZ), a non-narcotic analgesic, is used for the clinical management of moderate to severe pain. … Eadie-Hofstee analysis of [3H]NE uptake showed that both PTZs caused a significant decrease in the Vmax with little change in the apparent Km, suggesting non-competitive inhibition. …
NAID 130003362674

Related Pictures

★リンクテーブル★

リンク元	「noncompetitive」「非競合的」「noncompetitively」
拡張検索	「non-competitive inhibition」「non-competitive antagonist」「non-competitive inhibitor」
関連記事	「competitive」「n」「non」