### Understanding Kinetic Parameters in α-Chymotrypsin Reactions**Reaction Scheme:**The kinetic parameters for synthetic ester and peptide substrates of α-chymotrypsin are analyzed using the following reaction scheme:\[ \text{E + S} \underset{k_{-1}}{\overset{k_{1}}{\rightleftharpoons}} \text{ES} \overset{k_{2}}{\rightarrow} \text{ES'} \underset{P_1}{\rightarrow} \text{E + } P_2 \]- **ES**: Michaelis complex- **ES'**: Acyl-enzyme complex- **P1**: First product released- **P2**: Second productParameters include:- **k2**: Acylation rate constant- **k3**: Deacylation rate constant- **\(k_{cat}\)**: Maximum turnover number (calculated as \( \frac{k_{2} k_{3}}{k_{2} + k_{3}} \))### Substrate Definitions:- **N-Ac**: N-acetyl- **−CONH2**: Carboxamide- **−OC2H5**: Ethyl ester- **p-nitroanilide**: −NH−C6H4−NO2### Kinetic Parameters Table:| Substrate | \(k_2\) (s\(^{-1}\)) | \(k_3\) (s\(^{-1}\)) | \(k_{cat}\) (s\(^{-1}\)) | \(K_M\) (mM) | \(\frac{k_{cat}}{K_M}\) (mM\(^{-1}\) s\(^{-1}\)) ||--------------------------|----------------------|----------------------|--------------------------|--------------|-------------------------------------|| N-Ac-Trp-OC2H5 | 3.5 | 0.84 | 0.82 | 0.08 | 10.3 || N-Ac-Phe-OC2H5 | 13.0 | 2.2 | 1.9 | 1.3 | 1.5 || N-Ac-Leu-OC2H5 | 3.2 |

Chymotrypsin catalyzed peptide bond hydrolysis takes place in 2 phases after the enzyme binds the…

Answered: The value of kcat for N-Ac-Phe-OC₂H5 is…

Biochemistry

9th Edition

ISBN:9781319114671

Author:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.

Publisher:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.

Chapter1: Biochemistry: An Evolving Science

Section: Chapter Questions

Problem 1P

See similar textbooks

Similar questions

A seven-residue peptide was found to have an amino acid composition including glu, val, Lys, met, leu, and trp (there is more than one copy of one amino acid). Several reactions on samples of the peptide resulted in the following: a) Trypsin has no effect on the heptapeptide. b) If one cycle of Edman degradation provides the PTH derivative shown below, what does this tell you about the oligopeptide under investigation? [image] c) Chymotrypsin treatment yields a dipeptide, a tetrapeptide, and a free amino acid. Possibilities? d) The tetrapeptide contains val, lys, and met (only). What information does this give you? e) Cyanogen bromide treatment generates a dipeptide, a tetrapeptide, and free Lys. f)What is the sequence of the peptide?
You have isolated a new protease that cleaves peptide bonds on the carboxyl side of Asp and Glu. Based on the enzyme's inactivation by DIPF, you suspect that it may utilize a mechanism similar to chymotrypsin. The difference in specificity might be explained by the absence of the S1 binding pocket. replacement of serine 195 with a positively charged residue. presence of a positively charged residue in the S1 binding pocket. presence of a negatively charged residue in the S1 binding pocket.
When alanine undergoes transamination with oxaloacetate, alanine is first converted to alpha-keto acid. The enzyme uses PLP as a cofactor. Suggest a mechanism for this conversion starting with Schiff base PLP-ENZ. Remember to name the resulting alpha-keto acid.
Suppose you discover that bacteria that express OmpF have concentrations of <0.1uM of ciprofloxacin in the cytosol but those without this substance have concentrations of up to 50uM in the cytosol by the time they die. What does this tell you about the function of the isolated substance, OmpF, which you suspected from the start was related to quinolone resistance? How is the OmpF structure optimized for this function? Which amino acids in OmpF are suited to each aspect of its function? The structure of ciprofloxacin is shown below for reference.
The purified OXA-M290 enzyme can now be tested to determine which β-lactamase inhibitor is most effective. This inhibitor could be prescribed in combination with a β-lactam antibiotic to treat the infection caused by the E. coli KGH1 strain. Before testing inhibitors against OXA-M290, the kinetic activity of this enzyme must first be measured. The activity of OXA-M290 is measured using nitrocefin, a chromogenic β-lactam antibiotic. When nitrocefin is hydrolyzed by a β-lactamase, it changes from yellow to red in colour. The nitrocefin hydrolysis product has an extinction coefficient of 20,500 M-1 cm-1 at 486 nm. The hydrolysis of 60 μM nitrocefin by 1 nM OXA-M290 is monitored using a microplate reader. The absorbance of the wells in the plate is measured at 486 nm every 30 seconds. This experiment is carried out with three replicates, generating the following data: Time (min) Absorbance of Replicate 1 Absorbance of Replicate 2 Absorbance of Replicate 3 0.5 0.0984…
You are studying how your Lys-Val-Thr tripep de interacts with another pep de, which places an Asp in close proximity to the Lys on your pep de. How would the presence of an Asp side chain affect the pKa of the Lys side chain? Briefly explain your reasoning. (remember pKas are rela ve, pKa=log([H+][A-]/[HA])
The diagram below shows the substrate binding cleft for a protease, providing the substrate structure, and indicating the residues (using one-letter code) that line the four specificity pockets. 1 M F H₂N K R IZ 2 3 P F S W оо E 4 The protease is known to cleave the amide linkage between W and E residues for substrates containing the WEFD sequence. Using 3-letter code with amino acids linked by a "dash" (ex. GLY-ALA), the N-terminal product is A and the C-terminal product is A
The enzymatic activity of PFK1 is generally measured by set- ting up a coupled enzyme assay system whereby aldolase, triose phos- phate isomerase, and glycerol-3-phosphate dehydrogenase are added to the assay mixture. For the latter enzyme, NADH is added and its change in concentration is readily monitored at 340 nm. Write the chain of reactions catalyzed by these enzymes using structural formulas, label substrates and products, and explain why the coupled en- zyme assay system leads to oxidation of NADH. While the chain of reac- tions is similar to those in glycolysis, there is a critical difference because of the dehydrogenase enzyme. Describe how this enzyme causes the chain of reactions to differ from those in glycolysis.
Draw the tetrapeptide Met-Ile-Lys-Glu at a ph of 7?
Why is triose phosphate isomerase considered to be catalytically perfect?
Since all of the B-lactams that you have tested are susceptible to hydrolysis by PAESBL-1, the hospital will not be able to use a single 8-lactam to combat this P. aeruginosa isolate. You need to consider alternative strategies. From the following list, select all of the strategies that might successfully overcome the broad substrate specificity PAESBL-1: Check all that apply. using multiple B-lactams simultaneously (e.g., rather than treating with amoxicillin alone, treat with the three B-lactams: amoxicillin, cephalothin, and imipenem). O using a reversible inhibitor of PAESBL-1 instead of a 8-lactam. Treat future infections by O combining a reversible inhibitor of PAESBL-1 with one or more 8-lactams. O using an irreversible inhibitor of PaESBL-1 instead of a B-lactam. O combining an irreversible inhibitor of PAESBL-1 with one or more -lactams. O O O O
Put these steps in the mechanism of chymotrypsin catalysis in order from first to last. Note that some references may not break out each of these steps individually, but all steps should be ordered. There will be eight steps.

SEE MORE QUESTIONS

Recommended textbooks for you

Biochemistry

ISBN:

9781319114671

Author:

Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.

Publisher:

W. H. Freeman

Lehninger Principles of Biochemistry

Biochemistry

ISBN:

9781464126116

Author:

David L. Nelson, Michael M. Cox

Publisher:

W. H. Freeman

Fundamentals of Biochemistry: Life at the Molecul…

Biochemistry

ISBN:

9781118918401

Author:

Donald Voet, Judith G. Voet, Charlotte W. Pratt

Publisher:

WILEY

Biochemistry

ISBN:

9781319114671

Author:

Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.

Publisher:

W. H. Freeman

Lehninger Principles of Biochemistry

Biochemistry

ISBN:

9781464126116

Author:

David L. Nelson, Michael M. Cox

Publisher:

W. H. Freeman

Fundamentals of Biochemistry: Life at the Molecul…

Biochemistry

ISBN:

9781118918401

Author:

Donald Voet, Judith G. Voet, Charlotte W. Pratt

Publisher:

WILEY

Biochemistry

ISBN:

9781305961135

Author:

Mary K. Campbell, Shawn O. Farrell, Owen M. McDougal

Publisher:

Cengage Learning

Biochemistry

ISBN:

9781305577206

Author:

Reginald H. Garrett, Charles M. Grisham

Publisher:

Cengage Learning

Fundamentals of General, Organic, and Biological …

Biochemistry

ISBN:

9780134015187

Author:

John E. McMurry, David S. Ballantine, Carl A. Hoeger, Virginia E. Peterson

Publisher:

PEARSON

SEE MORE TEXTBOOKS