Explain how two different cell types from the same organism will have identical genomes but may have vastly divergent proteomes
1. Explain how two different cell types from the same organism will have identical genomes but may have vastly divergent proteomes.
2. suppose that you precipitate a protein with 1 M (NH4)2SO4 and that you wish to reduce the concentration of the (NH4)2SO4. You take 1 ml of your sample and dialysis it in 1000 ml of buffer. At the end of dialysis, what is the concentration of (NH4)2SO4 in your sample? How could you further lower the (NH4)2SO4 concentration?
<link is hidden> a 70-kDa muscle protein sediments moves slowly than does hemoglobin(65 kDa) their sedimentation coefficients are 2.6S and 4.31S, respectively. which structural feature of tropomyosin accounts for its slow sedimentation?
4. what is dependence of the sedimentation coefficients “s” of a spherical protein on its mass? how much more rapidly does 80-kDa protein sediment than does 40-kDa protein?
The relative electrophoretic mobilities of a 30-kd protein and a 92-kd protein used as standards on an SDS polyacrylamide gel are 0.80 and 0.41, respectively. What is the molecular weight of a protein having a mobility of 0.62 on the gel?
6. In the course of purifying an enzyme, a researcher performs a purification step that results in an increase in the total activity to a value greater than that present in the original crude extract. Explain how the amount of total activity might increase?
<link is hidden> numbers of different peptides can be synthesized in a small area on a solid support. This high-density array can then be probed with a fluorescence-labeled protein to find out which peptides are recognized. The binding of an antibody to an array of 1024 different peptides occupying a total area the size of a thumbnail is shown in the adjoining illustration. How would you synthesize such a peptide array? (Hint: Use light instead of acid to deprotect the terminal amino group in each round of synthesis.)
8. Determine the sequence of a peptide consisting of 14 amino acids on the basis of the following data.
Amino acid composition: (4S,2L,F,G,I,K,M,T,W,Y)
N-terminal analysis: S
Carboxypeptidase digestion: L
Trypsin digestion: (3S,2L,F,I,M,T,W) (G,K,S,Y)
Chymotrypsin digestion: (F,I,S) (G,K,L) (L,S) (M,T) (S,W) (S,Y)
N-terminal analysis of (F,I,S) peptide: S
Cyanogen bromide treatment: (2S,F,G,I,K,L,M*,T,Y) (2S,L,W)
M*, methionine detected as homoserine