1. Requirements of Active Sites in Enzymes The active site of an enzyme usually consists of a pocket on the enzyme surface lined with amino acid side chains necessary to bind the substrate and catalyze its chemical transformation. Carboxypeptidase, which sequentially removes the carboxyl-terminal amino acid residues from its peptide substrates, consists of a síngle chain of 307 amino acids. The two essential catalytic groups in the active site are furnished by Arg145 and Glu²7º. (a) If the carboxpeptidase chain were a perfect a-helix, how far apart (in nanometers) would Arg45 and Glu²7º be? Hint: In an æ-helix, there is 1.5 Å translation of the backbone per residue (Chapter 3). (b) Explain how it is that these two amino acids, so distantly separated in the sequence, can catalyze a reaction occurring in the space of a few tenths of a nanometer. ,270

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
icon
Related questions
Question

Answer b and c

## Requirements of Active Sites in Enzymes

The active site of an enzyme usually consists of a pocket on the enzyme surface lined with amino acid side chains necessary to bind the substrate and catalyze its chemical transformation. Carboxypeptidase, which sequentially removes the carboxyl-terminal amino acid residues from its peptide substrates, consists of a single chain of 307 amino acids. The two essential catalytic groups in the active site are furnished by Arg¹⁴⁵ and Glu²⁷⁰.

### Questions

1. **If the carboxypeptidase chain were a perfect α-helix, how far apart (in nanometers) would Arg¹⁴⁵ and Glu²⁷⁰ be?**
   
   *Hint: In an α-helix, there is 1.5 Å translation of the backbone per residue (Chapter 3).*

2. **Explain how it is that these two amino acids, so distantly separated in the sequence, can catalyze a reaction occurring in the space of a few tenths of a nanometer.**

3. **If only these two catalytic groups are involved in the mechanism of hydrolysis, why is it necessary for the enzyme to contain such a large number of amino acid residues?**
Transcribed Image Text:## Requirements of Active Sites in Enzymes The active site of an enzyme usually consists of a pocket on the enzyme surface lined with amino acid side chains necessary to bind the substrate and catalyze its chemical transformation. Carboxypeptidase, which sequentially removes the carboxyl-terminal amino acid residues from its peptide substrates, consists of a single chain of 307 amino acids. The two essential catalytic groups in the active site are furnished by Arg¹⁴⁵ and Glu²⁷⁰. ### Questions 1. **If the carboxypeptidase chain were a perfect α-helix, how far apart (in nanometers) would Arg¹⁴⁵ and Glu²⁷⁰ be?** *Hint: In an α-helix, there is 1.5 Å translation of the backbone per residue (Chapter 3).* 2. **Explain how it is that these two amino acids, so distantly separated in the sequence, can catalyze a reaction occurring in the space of a few tenths of a nanometer.** 3. **If only these two catalytic groups are involved in the mechanism of hydrolysis, why is it necessary for the enzyme to contain such a large number of amino acid residues?**
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 3 steps with 1 images

Blurred answer
Recommended textbooks for you
Biochemistry
Biochemistry
Biochemistry
ISBN:
9781319114671
Author:
Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.
Publisher:
W. H. Freeman
Lehninger Principles of Biochemistry
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…
Fundamentals of Biochemistry: Life at the Molecul…
Biochemistry
ISBN:
9781118918401
Author:
Donald Voet, Judith G. Voet, Charlotte W. Pratt
Publisher:
WILEY
Biochemistry
Biochemistry
Biochemistry
ISBN:
9781305961135
Author:
Mary K. Campbell, Shawn O. Farrell, Owen M. McDougal
Publisher:
Cengage Learning
Biochemistry
Biochemistry
Biochemistry
ISBN:
9781305577206
Author:
Reginald H. Garrett, Charles M. Grisham
Publisher:
Cengage Learning
Fundamentals of General, Organic, and Biological …
Fundamentals of General, Organic, and Biological …
Biochemistry
ISBN:
9780134015187
Author:
John E. McMurry, David S. Ballantine, Carl A. Hoeger, Virginia E. Peterson
Publisher:
PEARSON