1. Posttranslational Modifications (3 points) The following questions refer to t
ID: 199233 • Letter: 1
Question
1. Posttranslational Modifications (3 points)
The following questions refer to the posttranslational modifications of the tetrape[tide shown below:
SAYS
a) A hypothetical enzyme aminates the tyrosine. Propose an advantage this could provide to the cell producing this peptide.
b) An enzyme is known to phosphorylate the peptide to enzyme its biological activity. What type of enzyme would this be?
c) Another enzyme is also expressed by the cell to remove the phosphate when the peptide is no longer needed to be optimally active. What type of enzyme would this be?
d) Suppose yet another enzyme alkylates the serine residues of the peptide. Which non-covalent interactions would be increased due to this post translational modification?
Explanation / Answer
A- Aminato of tyrosine leads to overall positive charge on the peptide. This positive charge helps in growing the cells in slightly acidic condition.
B- KInases are the enzyme which phosphorylates the protein they use Pi from ATP and phosphorylated serine, threonine or tyrosine residues of the protein
C- Phosphatase is the enzymes which dephosphorylate the amino acid by removing phosphates group form the amino acid.
D- Alkylation of the serine residue makes the peptide hydrophobic as an alkyl group is hydrophilic. Hence Hydrophobic interaction will be increase upon alkylating the peptide
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.