Optimal Duration of the Preincubation Phase in Enzyme Inhibition Experiments

2020 ◽  
Author(s):  
Petr Kuzmic
Keyword(s):  
Enzyme Inhibition ◽  
Dose Response ◽  
Enzyme Inhibitor ◽  
Single Point ◽  
Association Rate ◽  
Weakly Bound ◽  
Inhibitor Complex ◽  
Dissociation Equilibrium ◽  
Optimal Duration ◽  
Algebraic Formula

This report describes an algebraic formula to calculate the optimal duration of the pre-incubation phase in enzyme-inhibition experiments, based on the assumed range of expected values for the dissociation equilibrium constant of the enzyme–inhibitor complex and for the bimolecular association rate constant. Three typical experimental scenarios are treated, namely, (1) single-point primary screening at relatively high inhibitor concentrations; (2) dose-response secondary screening of relatively weakly bound inhibitors; (3) dose-response screening of tightly-bound inhibitors.

scholarly journals Optimal Duration of the Preincubation Phase in Enzyme Inhibition Experiments

2020 ◽  
Author(s):  
Petr Kuzmic
Keyword(s):  
Enzyme Inhibition ◽  
Dose Response ◽  
Enzyme Inhibitor ◽  
Single Point ◽  
Association Rate ◽  
Weakly Bound ◽  
Inhibitor Complex ◽  
Dissociation Equilibrium ◽  
Optimal Duration ◽  
Algebraic Formula

This report describes an algebraic formula to calculate the optimal duration of the pre-incubation phase in enzyme-inhibition experiments, based on the assumed range of expected values for the dissociation equilibrium constant of the enzyme–inhibitor complex and for the bimolecular association rate constant. Three typical experimental scenarios are treated, namely, (1) single-point primary screening at relatively high inhibitor concentrations; (2) dose-response secondary screening of relatively weakly bound inhibitors; (3) dose-response screening of tightly-bound inhibitors.

m-[o-(2-Chloro-5-Fluorosulfonylphenylureido)Phenoxybutoxy]Benzamidine: Affinity Labeling Reagent Which Can Identify Secondary Binding Sites of Coagulation Complement and Fibrinolytic Serine Proteases

1979 ◽  
Author(s):  
D Bing ◽  
D Robison ◽  
J Andrews ◽  
R Laura
Keyword(s):  
Binding Sites ◽  
Serine Proteases ◽  
Enzyme Inhibitor ◽  
Molecular Model ◽  
Factor Xa ◽  
Affinity Labeling ◽  
Catalytic Center ◽  
Inhibitor Complex ◽  
Polypeptide Chains ◽  
Kinetics Of

We have determined that m-[o-(2-chloro-5-fluorosulfonylphenylureido)phenoxybutoxy]benza-midine [mCP(PBA)-F] is an affinity labeling reagent which labels both polypeptide chains of thrombin, factor Xa, complement component CIS and plasmin. As this means it is reacting outside of the catalytic center, we have called this reagent an exo-site affinity labeling reagent. Progressive irreversible inhibition of these enzymes by this reagent is rapid (k1st 2.5-4.6 x 10-3sec-1), the kinetics of inactivation are consistent with inhibition proceding via formation of a specific enzyme-inhibitor complex analogous to a Michaelis-Menton complex (KL - 115-26 μM), and diisopropylfluorophosphate or p-amidino-phenylmethanesulfonyfluoride Prevent labeling by [3H]mCP(PBA)-F. A molecular model of mCP(PBA)-F shows that the reactive SO2F group can be 17 A from the cationic amidine. The data are consistent with the hypothesis that both peptide chains are required for the specific proteolytic activity exhibited by these proteases and that the peptide chain which does not contain the active site serine is close to the catalytic center. (Supported by NIH and AHA grants

A Very Short Hydrogen Bond Provides Only Moderate Stabilization of an Enzyme-Inhibitor Complex of Citrate Synthase

Biochemistry ◽  
1994 ◽  
Vol 33 (25) ◽  
pp. 7753-7759 ◽  
Author(s):  
Ken C. Usher ◽  
S. James Remington ◽  
David P. Martin ◽  
Dale G. Drueckhammer
Keyword(s):  
Hydrogen Bond ◽  
Citrate Synthase ◽  
Enzyme Inhibitor ◽  
Inhibitor Complex ◽  
Short Hydrogen Bond

scholarly journals Kinetic properties of the primary inhibitor of plasmin from human plasma

1977 ◽  
Vol 163 (2) ◽  
pp. 389-391 ◽  
Author(s):  
U Christensen ◽  
I Clemmensen
Keyword(s):  
Human Plasma ◽  
Enzyme Inhibitor ◽  
Kinetic Properties ◽  
Inhibitor Complex ◽  
Rapid Formation ◽  
Plasmin Inhibitor

The interaction of human plasmin with the newly discovered alpha2-plasmin inhibitor was investigated. It was found from rate measurements that the reaction involves the rapid formation of a first enzyme-inhibitor complex, followed by the slow irreversible transition to another complex. L-Lysine influences the first step, but not the second.

Enzyme-Inhibitor Complex in a Tryptophan-Requiring Mutant of Neurospora crassa

Science ◽  
1957 ◽  
Vol 126 (3282) ◽  
pp. 1068-1069 ◽  
Author(s):  
S. R. SUSKIND ◽  
L. I. KUREK
Keyword(s):  
Neurospora Crassa ◽  
Enzyme Inhibitor ◽  
Inhibitor Complex

scholarly journals Structure of Enzyme-Inhibitor Complex Determined by Neutron Crystallography

2013 ◽  
Vol 55 (1) ◽  
pp. 47-51
Author(s):  
Taro TAMADA ◽  
Motoyasu ADACHI ◽  
Kazuo KURIHARA ◽  
Ryota KUROKI
Keyword(s):  
Enzyme Inhibitor ◽  
Inhibitor Complex ◽  
Neutron Crystallography

Abstract P190: Antihypertensive Monotherapy And Risk Of Depression Incidence

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Anwar Alnakhli ◽  
Richard Shaw ◽  
Daniel Smith ◽  
Sandosh Padmanabhan
Keyword(s):  
Dose Response ◽  
Enzyme Inhibitor ◽  
Previous History ◽  
Cox Proportional Hazards ◽  
Recent Theory ◽  
Defined Daily Dose ◽  
Response Relationship ◽  
Dose Response Relationship ◽  
Antihypertensive Medications ◽  
Increased Risk

Background: Recent theory suggests that antihypertensive medications may be useful as repurposed treatments for mood disorders, however, empirical evidence is inconsistent Objective: We aimed to assess the risk of depression incidence as indicated by first-ever prescription of antidepressant in patients newly exposed to antihypertensive monotherapy and whether there is a dose-response relationship. Method: This study enrolled 2406 new users of antihypertensive monotherapy aged between 18 and 80 years with no previous history of antidepressant prescriptions. The exposure period (EP) to antihypertensive medication was fixed at one year starting from the first date of antihypertensive prescription between Jan 2005 and Mar 2012 and extended up to 12 months. Follow-up commence after the EP until March 2013. To test for dose-response relationship the cumulative defined daily dose (cDDD) of antihypertensive during the EP were stratified into tertiles. Cox proportional hazards models were used to estimate hazard ratios (HR) for depression incidence. Results: Among the five major classes of antihypertensive medications, calcium channel blocker (CCB) had the highest risk of developing depression after adjusting for covariates (HR = 1.40 95%CI 1.11,1.78) compared to angiotensin-converting enzyme inhibitor (ACEI). Angiotensin-receptor blocker (ARB) treatment showed higher risk of depression incidence with tertile 2(HR= 1.46, 95%CI 0.88,2.44) and tertile 3 (HR= 1.75, 95%CI 1.03,2.97) compared to tertile 1 of cDDD. Conclusion: Our findings confirmed previous evidence suggesting that CCB is associated with increased risk of depression incidence compared to ACEI. Risk of developing depression is also linked to ARB, though it might be dose dependent.

TWO-SIDE IMMUNOASSAYS OF ENZYME-INHIBITOR COMPLEXES FOR THE DIAGNOSIS OF THROMBOPHILIC STATES

1987 ◽  
Author(s):  
H Bleyl
Keyword(s):  
Heart Surgery ◽  
Enzyme Inhibitor ◽  
Open Heart Surgery ◽  
Coagulation Cascade ◽  
Clotting Factors ◽  
Inhibitor Complex ◽  
At Iii ◽  
Complex Measurement ◽  
Sandwich Assays ◽  
Time Of Admission

The diagnosis of prethrombotic states requires methods which detect products of intravasal activation of the coagulation cascade.Two-side immunoassays for antithrombin complexes with clotting factors were developed (IXi-AT, Xi-AT, IIi- AT). These sandwich assays permit the diagnosis of hypercoagulability in the presence or absence of heparin. The biological half live time of the thrombin-antithrombin-complex was found to be about 15 min. Healthy young men 20-25 years old (n=30) have a thrombin-antithrombin-complex concentration of 0.4 ± 0.2 mU/ml thrombin equivalent (S 2238). Patients with acute myocardial infarction (n=40) showed at the time of admission to the hospital up to 10-fold (n=14), up to 100-fold (n=13) more than 100-fold (n=13) elevated thrombin-antithrombin-complex concentrations. Patients with gastrointestinal cancer showed sometime excessive elevated enzyme-inhibitor complexes.No correlation was found between thromboplastine time (Quick) and complex concentration in patients under anticoagulant therapy with dicumarole. In patients under dialysis as well as in patients under open heart surgery with extracorporal circulation, the biocompatibility can be monitored by inhibitor complex measurement.

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