In some proteins that contain two or more cysteine amino acids, the formation of
ID: 146846 • Letter: I
Question
In some proteins that contain two or more cysteine amino acids, the formation of disulfide bonds are necessary to achieve a folded and stable protein. The endoplasmic reticulum is an oxidative environment whereas the cytosol is a reducing environment. What organelles do animal cells use to host the synthesis of insulin and why? If you want to engineer an animal cell to produce insulin and secrete it to the extracellular matrix, what organelles are required to perform this task and obtain a functional secreted insulin?
Explanation / Answer
Q.1
Disulfide bonds do not form in cytosol due to reducing environment. Therefore disulfide bond formation occurs only in ER, catalyzed by protein disulfide isomerase.
Protein folding occur in the lumen of the endoplasmic reticulum (ER), including three types of covalent modifications: signal peptide removal, N-linked glycosylation, and disulfide bond formation.
Protein disulfide isomerase (PDI) is an enzyme found in the endoplasmic reticulum in eukaryotes.It catalyzes the formation and breakage of disulfide bonds between cysteine residues of insulin protein to stabilize its folded structure.
Q.2
Nucleus - transcription of insulin gene,
Rough ER - translation of insulin mRNA,
Golgi, Vesicles - transport of insulin to extracellular matrix.
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.