3. (a) In Bakers yeast there are two variants of cytochrome c, a heme containing protein of 108 amino acid residues that catalyzes electron transfer reactions in mitochondria. The two forms of cyto- chrome c known as iso-1 and iso-2 cytochrome c differ in 17 of the 108 amino acids. The content of proton dissociable side chains for the two cytochromes c is given in the table below: Side chain pka iso-1 cytochrome c Ziso-1 iso-2 cytochrome c 12.5 3 4.0 4 8.0 1 4.0 4 6.0 4 10.0 16 9.0 7.0 4.0 Arginine Aspartate Cysteine Glutamate Histidine Lysine Tyrosine -NH3Ⓡ -COOH 5 1 1 What is the overall electrostatic charge on each cytochrome at pH 8? (b) To the right is a diagram of the chemical groups in carboxymethyl-cellulose and DEAE-cellulose that are used for ion exchange chromatography to purify proteins. At pH 8 which chromatographic resin has to be used to separate iso-1-cytochrome c from iso-2-cytochrome c from a lysate of yeast cells? If the proteins are separated by application of a concentration gradient of NaCl applied to the column, which ion Na or Cl displaces the proteins from the binding sites on the chromatographic resin? 0 0 carboxymethyl cellulose OH 0 350737511 CH 3 ΘΝΗ HO Ziso-2 HỌC NH H3C₁ 2-(diethylamino)ethyl cellulose (DEAE cellulose) (c) Which protein iso-1-cytochrome c or iso-2-cytochrome c will be the first to be eluted from the column and why? (d) Both cytochromes in their ferrous form are substrates of yeast cytochrome c peroxidase (CCP) and react optimally with this enzyme at pH 8 forming a Michaelis complex of 1:1 stoichiometry (CcP:cyt c). If the isoionic point of the peroxidase is 5.25, what will be the overall electrostatic charge on the peroxidase enzyme for this reaction to occur, positive or negative?

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
3. (a)
In Bakers yeast there are two variants of cytochrome c, a heme containing protein of 108
amino acid residues that catalyzes electron transfer reactions in mitochondria. The two forms of cyto-
chrome c known as iso-1 and iso-2 cytochrome c differ in 17 of the 108 amino acids. The content of
proton dissociable side chains for the two cytochromes c is given in the table below:
Side chain
pka iso-1 cytochrome c
Ziso-1
iso-2 cytochrome c
12.5
3
4.0
4
8.0
4.0
6.0
10.0
9.0
7.0
4.0
Arginine
Aspartate
Cysteine
Glutamate
Histidine
Lysine
Tyrosine
-NH3Ⓡ
-COOH
1
4
4
16
5
1
1
What is the overall electrostatic charge on each cytochrome at pH 8?
(b)
To the right is a diagram of the chemical groups
in carboxymethyl-cellulose and DEAE-cellulose that are
used for ion exchange chromatography to purify proteins.
At pH 8 which chromatographic resin has to be used to
separate iso-1-cytochrome c from iso-2-cytochrome c from
a lysate of yeast cells? If the proteins are separated by
application of a concentration gradient of NaCl applied to
the column, which ion Na or Cl displaces the proteins
from the binding sites on the chromatographic resin?
carboxymethyl
cellulose
35O737511
0
H3C
CH 3
ΘΝΗ
0
HO
Ziso-2
HỌC TỈNH
H3C 2-(diethylamino)ethyl
cellulose
(DEAE cellulose)
(c) Which protein iso-1-cytochrome c or iso-2-cytochrome c will be the first to be eluted from the
column and why?
(d)
Both cytochromes in their ferrous form are substrates of yeast cytochrome c peroxidase
(CCP) and react optimally with this enzyme at pH 8 forming a Michaelis complex of 1:1 stoichiometry
(CcP:cyt c). If the isoionic point of the peroxidase is 5.25, what will be the overall electrostatic charge
on the peroxidase enzyme for this reaction to occur, positive or negative?
Transcribed Image Text:3. (a) In Bakers yeast there are two variants of cytochrome c, a heme containing protein of 108 amino acid residues that catalyzes electron transfer reactions in mitochondria. The two forms of cyto- chrome c known as iso-1 and iso-2 cytochrome c differ in 17 of the 108 amino acids. The content of proton dissociable side chains for the two cytochromes c is given in the table below: Side chain pka iso-1 cytochrome c Ziso-1 iso-2 cytochrome c 12.5 3 4.0 4 8.0 4.0 6.0 10.0 9.0 7.0 4.0 Arginine Aspartate Cysteine Glutamate Histidine Lysine Tyrosine -NH3Ⓡ -COOH 1 4 4 16 5 1 1 What is the overall electrostatic charge on each cytochrome at pH 8? (b) To the right is a diagram of the chemical groups in carboxymethyl-cellulose and DEAE-cellulose that are used for ion exchange chromatography to purify proteins. At pH 8 which chromatographic resin has to be used to separate iso-1-cytochrome c from iso-2-cytochrome c from a lysate of yeast cells? If the proteins are separated by application of a concentration gradient of NaCl applied to the column, which ion Na or Cl displaces the proteins from the binding sites on the chromatographic resin? carboxymethyl cellulose 35O737511 0 H3C CH 3 ΘΝΗ 0 HO Ziso-2 HỌC TỈNH H3C 2-(diethylamino)ethyl cellulose (DEAE cellulose) (c) Which protein iso-1-cytochrome c or iso-2-cytochrome c will be the first to be eluted from the column and why? (d) Both cytochromes in their ferrous form are substrates of yeast cytochrome c peroxidase (CCP) and react optimally with this enzyme at pH 8 forming a Michaelis complex of 1:1 stoichiometry (CcP:cyt c). If the isoionic point of the peroxidase is 5.25, what will be the overall electrostatic charge on the peroxidase enzyme for this reaction to occur, positive or negative?
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 5 steps with 1 images

Blurred answer
Similar questions
  • SEE MORE QUESTIONS
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