In biochemistry laboratories, phenylmethylsulfonyl fluoride (PMSF) is a serine proteaseinhibitor commonly added to cell homogenates to protect proteins from digestion formserine proteases that are released when cell membranes and cell organelles arebroken.=S-FPMSF: phenylmethylsulfonyl fluoride1. Based on our discussion of covalent inhibition of acetylcoline, esterase bydiisopropylfluorophosphate, predict the effect of PMSF on chymotrypsin and predict howPMSF will modify the chymotrypsin active site. Justify your answer based on thepropertied of the active sites of the enzymes.

In order to understand how PMSF (Phenylmethylsufonyl fluoride) inhibits chymotrypsin, we need to…

Answered: In biochemistry laboratories,…

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

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Similar questions

Using the catalytic mechanism of serine proteases, draw and label a reaction coordinate diagram/graph of the chymotrypsin-catalyzed hydrolysis of a peptide bond.
AMP- PNP is a non-hydrolyzable ATP analog that cannot be metabolized by cells. Taurocholate is a bile acid that helps emulsify fats. When taurocholate is added to hepatocyte cell culture, it accumulates in those cells. The graph below shows the rate of cellular accumulation of the drug taurocholate in the presence of either ATP, ATP, or AMP-PNP. Based on this date, describe the mechanism by which taurocholate enters the cell. Justify the answer.
Diisopropylphosphofluoridate (DIPF) inactivates chymotrypsin by covalently modifying serine 195. Which statement is true of DIPF's inhibitory mechanism? DIPF randomly modifies all serine residues on the protein, and if enough is added, the serine in the active site will eventually be modified. DIPF approaches serine 195 more closely than other substrates. DIPF looks like the substrate for chymotrypsin and binds in the active site as a competitive inhibitor. Serine 195 is in an environment that gives it a higher than normal reactivity with respect to DIPF.
In some organisms, isoleucine can be synthesized in a multi-step procedure (a series of enzymatic reactions), beginning with a molecule of threonine. Keeping that in mind explain the experimental results below. Amount of endproduct Activity of threonine (isoleucine) deaminase None Low Medium High Very high High Moderate Very low
Dihydrofolate reductase (DHFR) is an enzyme that reduces 7,8-dihydrofolate (DHF) to 5,6,7,8- tetrahydrofolate, a step in the biosynthesis of thymidine. Methotrexate (MTX) a structural analogue of dihydrofolate, inhibits this enzyme. MTX has been used in cancer therapies because the inhibition of DHFR restricts thymidine production required for cell division. In the absence of thymidine the cancerous cells cannot multiply. Using the following data of DHFR activity in the presence of MTX, i) Determine the inhibition mechanism of MTX and the maximum reaction rate. If Km for DHFR is 0.100 uM, what is K; ? ii) [DHF](MM) Rate w/200 nM Rate w/50 nM MTX (mMs-¹) Rate w/100 nM MTX MTX (mMs ¹) (mMs ¹) 3 7.38 5.56 3.72 6 8.84 7.38 5.55 9 9.46 8.29 6.65 12 9.79 8.84 7.38
The enzyme cytidine deaminase catalyzes the conversion of cytidine to uridine. Cytidine deaminase catalyzes the reaction through an addition of water across the cytidine 3,4-bond, forming a tetrahedral intermediate followed by the elimination of NH3 to form the product uridine. This is like the addition-elimination mechanism that we studied for adenosine deaminase. Cytidine deaminase НО. NH₂ N пOH OH cytosine R + H₂O cytidine The Km value for the substrate cytidine is 2.5 × 10-4 M, and the K; for competitive inhibition by the product uridine is 2.5 × 10-³ M. N R A reduced derivative of the product, 3,4,5,6-tetrahydrouridine was shown to be a fully reversible competitive inhibitor with a Ki of 2.4 x 10-7 M, a value approximately 10,000 times lower than that of the product uridine. NH₂ NH uridine HO. N R R = D-ribose HOH OH uridine 3NH uracil ring numbering H NH H H + NH3 H OH H 3,4,5,6-tetra- hydrouridine a.) Draw a structure of the intermediate that we predict to form during the…
the following is a coenzyme or cofactor involved in enzymatic reaction. identify the biochemical role that S-adenosylmethionine plays within a biochemical tranformation.
Small molecules are used as inhibitors of protein action - as drugs. They most often do this by blocking the active site within the protein. Potential drugs can be screened computationally to determine if they are strongly bound to the protein. Figure 1 shows a possible conformation of a candidate drug molecule, 4-bromo-2- carboxymethylamide-pyrrole (abbreviation: BCMAP) at the active site of a protein (abbreviation: PR). Figure 2 shows the full protein structure whilst figure 3 shows a known inhibitor of the protein at the site, overlayed with another calculated conformer of BCMAP. (a) Explain what types of interactions, both intermolecular and intramolecular, that a molecular mechanics forcefield must be able to describe in order to be able to accurately determine the geometry of BCMAP in the protein. Identify which interactions will be the most important to describe accurately. Figure 1.4-bromo-2-carboxymethylamide-pyrrole (BCMAP) (C, N, O, and Br atoms in yellow, blue, red, and…
UDP-glucuronosyltransferase enzymes bind the organic compound UDP-glucuronic acid (UDP-GA) in order to catalyse the transfer of a glucuronic acid group from UDP-GA to a drug molecule, releasing UDP from the active site as a product. UDP is then regenerated by the activity of another enzyme. What terms could be used to describe UDP-GA?
Match the enzymatic activity with the proper description within the ubiquitin-proteasome pathway. Drag and drop options on the right-hand side and submit. For keyboard navigation... SHOW MORE ✓ E1 E2 E3 Proteasome = ||| = ||| = ||| Degradation Ubiquitin-activating enzymes Ubiquitin-conjugating enzymes. Ubiquitin ligases
H CH₂ H₂C HC-CH3 CH₂ H H₂C (S) H₂C H CH₂ CH₂ CH₂ NH O C NH NH₂ a) Which of the following statements about this peptide are correct? Group of answer choices Treatment of this peptide with trypsin generates two products. This peptide is a substrate for carboxypeptidase A Treatment of this peptide with cyanogen bromide generates a pentapeptide and a tripeptide. Treatment of this peptide with chymotrypsin generates three products. Treatment of this peptide with elastase generates 2 products. None of the above statements are correct. b) What is the sequence of this peptide using one letter abbreviations? c) What is the pH which would correspond to the ionization of the peptide as drawn above? 1, 5, 7, 10, 14
Consider the metabolic pathway show below that converts substrate A to B with the enzyme A-ase, B to C with B-ase(I), and so forth. Acety/A-ase A-ase Acetate Deacetylase D Protease B-ase C-ase A-ase ABC- What is the mechanism of regulation of B-ase? Positive allostery Reversible Covalent modification Isoenzymes Proteolytic Activation Feedback Inhibition

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