#Question id: 1512

There is evidence that the accumulation of abnormal or damaged proteins due to impairment of the pathway contributes to a number of neurodegenerative diseases, including Alzheimer’s. In contrast, deliberately blocking the pathway in cancer cells could lead to a disruption of protein regulation that in turn could cause the apoptosis of the malignant cells. Accordingly, proteasome inhibitors have been developed for evaluation as anti-tumour agents against selected cancers. Bortezomib is one such inhibitor that targets the 26S proteasome, and in combination with other chemotherapeutic agents has been shown to have therapeutic potential. In contrast to the long-term control, there are several mechanisms by which the activity of an enzyme can be altered almost instantaneously:

A. Reversible inhibition by small molecules (drugs)

B. Product inhibition

C. Allosteric regulation

D. Reversible covalent modification

Which of the above mechanism follow the process of negative-feedback control and ADP-ribosylation respectively?