scholarly journals Enzyme Concentration, Substrate Concentration and Temperature based Formulas for obtaining intermediate values of the rate of enzymatic reaction using Lagrangian polynomial

2012 ◽  
Vol 1 (3) ◽  
Author(s):  
Nizam Uddin
Keyword(s):  
Substrate Concentration ◽  
Enzymatic Reaction ◽  
Enzyme Concentration

scholarly journals Factors like Dilution and Mixing Influence Enzymatic Reactions

2020 ◽  
Vol 19 (4) ◽  
Author(s):  
Mahin Basha Syed ◽  
Venkatanagraraju Erumalla
Keyword(s):  
Enzyme Activity ◽  
Substrate Concentration ◽  
Enzymatic Reaction ◽  
Enzyme Reaction ◽  
Enzyme Concentration ◽  
Enzymatic Reactions ◽  
First Report ◽  
Enzyme Substrate ◽  
Catalyzed Reactions ◽  
Enzyme Catalyzed Reactions

Enzyme-catalyzed reactions were influenced by many factors. The enzyme reacts with the substrate and converts it into products. Enzymes are influenced by temperature, pH, enzyme concentration, and substrate concentration. This paper evaluates the hypothesis of factors that may influence enzyme activity. Two more factors that affects enzyme activity are dilution and mixing. In enzyme-substrate reactions, the small amount of dilution and mixing will not affect the enzyme activity. Dilution and mixing do not slowdowns the enzyme reaction but it enhances the enzymatic reaction up to a certain limit. Increase in dilution results in less interaction of enzyme substrate, which causes a decrease in the rate of reactions. To the best of our knowledge, this is the first report to shows that, factors like mixing and dilution also affect enzyme and substrate reactions.

scholarly journals The determination of binding parameters when the total and free substrate concentrations are not approximately equal

1979 ◽  
Vol 179 (3) ◽  
pp. 697-700 ◽  
Author(s):  
N Gains
Keyword(s):  
Substrate Concentration ◽  
Graphical Method ◽  
Enzyme Concentration ◽  
Binding Parameters ◽  
Free Concentration ◽  
Equilibrium Binding ◽  
Substrate Concentrations

By using a standard graphical method values of Km and V may be found that are independent of the conditions and assumptions that the total substrate concentration approximates to its free concentration and that Km is much larger than the enzyme concentration. The procedure is also applicable to the determination of equilibrium binding parameters of a ligand to a macromolecule.

THEORY OF THE TRANSIENT PHASE IN AN ENZYME SYSTEM INVOLVING TWO ENZYME-SUBSTRATE COMPLEXES: THE CASE OF THE FORMATION OF PRODUCTS FROM THE FIRST COMPLEX

1959 ◽  
Vol 37 (4) ◽  
pp. 737-743 ◽  
Author(s):  
Ludovic Ouellet ◽  
James A. Stewart
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Active Site ◽  
Substrate Concentration ◽  
Enzyme System ◽  
Kinetic Scheme ◽  
Enzyme Concentration ◽  
Theoretical Treatment ◽  
Transient Phase ◽  
Enzyme Substrate

A theoretical treatment is worked out for the kinetic scheme[Formula: see text]in which the concentration of P1 is followed. The steady-state and transient phase equations are obtained subject to the condition that the substrate concentration is greatly in excess of the enzyme concentration. The conditions under which evidence in favor of this mechanism can be obtained from experimental data are discussed. Under certain conditions, the weight of the enzyme corresponding to one active site can be determined. Methods for the evaluation of the different constants are described.

scholarly journals Cyclodextrin Formation Initiated by Enzyme Debranching Reaction On Amylopectin Branch Chain Of Tapioka

2012 ◽  
Vol 12 (1) ◽  
pp. 15
Author(s):  
Amran Laga
Keyword(s):  
Substrate Concentration ◽  
Branching Process ◽  
Time Estimation ◽  
Enzyme Concentration ◽  
Straight Chain ◽  
Optimal Length ◽  
Debranching Enzyme ◽  
Concentration Estimation ◽  
Cyclic Product ◽  
Cyclic Reaction

Degradation of starch by the glucosyltransferase enzyme (CGTase) to produce the primary product of chainsplitting undergoes an intramolecular reaction without the participation of water molecule. From this process, α-1,4-Linked cyclic product, known as cyclodextrins, are formed. The aim of the research was to cut amylopectinbranch in order to produce one straight chain, to optimize cyclic reaction formation cyclodextrin by CGTase. Theresearch was devided into 3 stages; (1) debranching enzyme concentration estimation (5,10,15,20, and 25 unit/gram) and the length of otimum reaction to produce straight chain for 5 hours which sample was taken each hour,(2) reaction length time estimation to form cyclodextrin in order to use debranching products (straight chain) assubstrates, the reaction length for 360 minutes and sample taken each for 30 minutes, and (3) the best substrateconcentration for straight chain (20-40% w/v) to produce cyclodextrin. The result showed that enzyme concentrationtreatment and optimal length reaction will produce straight chain with enzyme concentration of 14 units/gram for3 hours and straight chain product of 20 units/gram for 1 hour with straight chain product of 83.5%. The optimumlength of reaction for cyclodextrin formation from amylose produced from the de-branching process was 240minutes. The amount of cyclodextrin produced was 143.45 g/L with conversion value of 47.81% at 30% (w/v)substrate concentration. Highest yield of cyclodextrin (154,28 g/L) and conversion value of 44.08% was obtained at35% (w/v) substrate concentration

Determination of serum aminotransferases: activation by pyridoxal-5'-phosphate in relation to substrate concentration.

1979 ◽  
Vol 25 (1) ◽  
pp. 55-59 ◽  
Author(s):  
J C Hafkenscheid ◽  
C C Dijt
Keyword(s):  
Enzymatic Activity ◽  
Serum Sample ◽  
Aspartate Aminotransferase ◽  
Substrate Concentration ◽  
Enzymatic Reaction ◽  
Reaction Medium ◽  
Aminotransferase Activity ◽  
Serum Aminotransferases ◽  
Stimulation Of

Abstract To investigate the activation of aspartate- and alanine aminotransferases by pyridoxal-5'-phosphate, we determined the enzymatic activity in serum in two different ways: (a) Preincubation of the serum alone or the serum with pyridoxal-5'-phosphate and starting the reaction by the addition of the serum sample or the serum sample + coenzyme, respectively. (b) Preincubation of the serum or the serum with pyridoxal-5'-phosphate in the reaction medium and starting the reaction by adding 2-oxoglutarate. There are only small differences in activities of both aminotransferases determined according to these two different methods. The stimulation by pyridoxal-5'-phosphate is also of the same order, when both methods are compared. Further, these enzymatic activities were measured with use of various concentrations of substrates. From our experiments we conclude that the degree of stimulation of the apoenzyme of the two enzymes is independent of which way the enzymatic reaction is carried out or the substrate concentration, except that aspartate aminotransferase activity is more stimulated by the coenzyme at higher 2-oxoglutarate concentrations.

Formation of radioactive diacylglycerol from radioisotope-labelled phosphatidylethanolamine by Escherichia coli extracts

1989 ◽  
Vol 67 (6) ◽  
pp. 288-292 ◽  
Author(s):  
H. Aubry ◽  
P. Proulx
Keyword(s):  
Escherichia Coli ◽  
Phospholipase C ◽  
Substrate Concentration ◽  
Incubation Medium ◽  
Isotope Ratio ◽  
Enzyme Concentration ◽  
Water Soluble ◽  
Ph Optimum ◽  
Direct Incorporation

Radioisotope-labelled phosphatidylethanolamine can be converted to radioactive diacylglycerol in the presence of added unlabelled diacylglycerol. With [14C-glycerol; 3H-acyl]phosphatidylethanolamine as substrate, the conversion to double-labelled diacylglycerol occurred without change in isotope ratio indicating that the whole diacylglycerol moiety of phosphatidylethanolamine was directly involved. With [3H-acyl; 32P]phosphatidylethanolamine, formation of [3H]diacylglycerol occurred without production of labelled water-soluble products and consequently no phospholipase C activity could be detected. Under similar conditions, a conversion of [14C-acyl]- or [3H-acyl]-diacylglycerol to labelled phosphatidylethanolamine could also be shown even in the presence of hydroxylamine. [14C-Glycerol; 3H-acyl] diacylglycerol was converted to double-labelled product without change in isotope ratio which again indicated a direct incorporation of the entire diacylglycerol molecule into phosphatidylethanolamine. Both types of conversions were dependent upon time, enzyme concentration, and substrate concentration, and both displayed a pH optimum of approximately 6 and required no added cofactors. In the presence of increasing concentrations of [14C-acyl]diacylglycerol, added to incubation medium containing [3H-acyl]phosphatidylethanolamine, equal amounts of [14C]phosphatidylethanolamine and [3H]diacylglycerol were formed which matched the decrease in [3H]phosphatidylethanolamine. From these results, we conclude that Escherichia coli has an enzyme that catalyses the exchange between the diacylglycerol moiety of phosphatidylethanolamine and free diacylglycerol, with complete sparing of the phosphoethanolamine moiety.Key words: diacylglycerol, phosphatidylethanolamine, exchange, Escherichia coli.

scholarly journals The glucoamylase of Coniophora cerebella

1967 ◽  
Vol 105 (2) ◽  
pp. 577-583 ◽  
Author(s):  
N. J. King
Keyword(s):  
Substrate Concentration ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Glucose Production ◽  
Enzyme Concentration ◽  
Polymer Chains ◽  
Branch Points ◽  
Amylolytic Enzyme ◽  
Concentration Of Ions ◽  
Activity Unit

1. The major amylolytic enzyme in culture filtrates of Coniophora cerebella grown in starch-containing media has been purified and characterized as a glucoamylase (EC 3.2.1.3). 2. The activity/unit wt. of protein was increased 11-fold and the enzyme showed one major component on polyacrylamide-gel electrophoresis. 3. The glucoamylase had optimum pH4·0–4·5. 4. Hg2+ completely inhibited the enzyme, but other ions tested had little effect on the activity at the concentration of ions used (5mm). 5. The action of the enzyme on amylopectin, amylose and maltose was studied. Hydrolysis proceeded by the stepwise removal of glucose units from the non-reducing ends of the polymer chains, and the enzyme was able to bypass or to hydrolyse the α-(1→6)-glucosidic linkages at branch points in the amylopectin molecule. Glucose was the only product found in digests of these substrates. 6. At the same substrate concentration (0·1%, w/v) and enzyme concentration, the initial rates of glucose production from amylopectin, amylose and maltose were in the proportions 40:10:1. 7. Km values at 40° and pH4·0 were calculated for the enzyme acting on amylopectin, amylose and maltose.

scholarly journals A recording viscometer for assaying mammalian collagenase

1983 ◽  
Vol 213 (1) ◽  
pp. 275-278
Author(s):  
H W Macartney ◽  
S R E Bates ◽  
N L Blumson ◽  
D Nelson ◽  
D Jamison ◽  
...  
Keyword(s):  
Substrate Concentration ◽  
Initial Velocity ◽  
Peptide Bond ◽  
Enzyme Concentration ◽  
Experimental Confirmation ◽  
Amino Groups ◽  
Soluble Collagen

A recording viscometer for monitoring the action of mammalian collagenase on soluble collagen is described. For this system, where only one peptide bond is cleaved per subunit, it is shown theoretically that the decrease in viscosity is proportional to the fraction of molecules cleaved. Experimental confirmation was obtained by parallel monitoring of hydrolysis by using the fluorescamine assay of liberated amino groups. The initial velocity of reaction is proportional to substrate concentration and enzyme concentration.

Study on the Process of the Reaction Catalyzed by Polyphenol Oxidase from Purple Sweet Potato

2014 ◽  
Vol 898 ◽  
pp. 153-156 ◽  
Author(s):  
Lu Gao ◽  
Li Chun Zhao ◽  
Ji Dong Duan ◽  
Yan Li Tao
Keyword(s):  
Sweet Potato ◽  
Polyphenol Oxidase ◽  
Substrate Concentration ◽  
Phosphate Buffer ◽  
Phosphate Buffer Solution ◽  
Enzyme Concentration ◽  
Buffer Solution ◽  
Purple Sweet Potato ◽  
The Relationship ◽  
Substrate Concentrations

The polyphenol oxidase (PPO) was extracted from fresh purple sweet potato (PSP) by phosphate buffer solution, and spectrophotometry method was applied in the experiment. The process of the reaction catalyzed by PPO with different substrate concentrations and the relationship between enzyme concentrations and PPO activity were mainly studied here. The result showed that the effect of enzyme concentration on PPO activity was stronger than that of substrate concentration on PPO activity.

scholarly journals Intensification of biokinetics of enzymes using ultrasound assisted methods: A critical review

2021 ◽  
Author(s):  
Altab Khan ◽  
Mohd Riyaz Beg ◽  
Pramod Waghmare
Keyword(s):  
Catalytic Activity ◽  
Enzymatic Reaction ◽  
Enzyme Concentration ◽  
Ultrasonic Transducers ◽  
Chemical Effects ◽  
Low Intensity Ultrasound ◽  
Ultrasonic Parameters ◽  
And Performance ◽  
Ultrasonic Reactors ◽  
Physical And Chemical

The use of low intensity ultrasound has gotten surprising consideration over the last decade as a method for enhancing the catalytic activity of enzyme. Ultrasounds have the potential to significantly influence the activity of the enzymatic processes, provided that the energy input is not too high to inactivate the enzyme. By providing the variation in parameters, various physical and chemical effects can be attained that can enhance the enzymatic reaction. Ultrasonic reactors are known for their application in bioprocesses. However, the potential of their applications is still limited broadly due to the lack of proper information about their operational and performance parameters. In this review, the detailed information about ultrasonic reactors is provided by defining the different types of reactors, number and position of ultrasonic transducers. Also, it includes mechanism of intensification and influence of ultrasonic parameters (intensity, duty cycle and frequency) and enzymatic factors (enzyme concentration, temperature and pH) on the catalytic activity of enzyme during ultrasound treatment.

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