Ubiquitin (Ub)

Ubiquitin(Ub) is a small protein that is composed of 76 amino acids. Ub is found only in eukaryotic organisms and is highly conserved. Ub can exist either in free form or as part of a complex with other proteins. In the latter case, Ub is attached(conju­gated) to proteins through a covalent bond between the glycine at the Cterminal end of Ub and the side chains of lysine on the proteins; Ubiquitination. Ub functions to regulate protein turnover in a cell by closely regulating the degradation of specific proteins. Ubiquitin has been immunohistoche­mically localized to a number of pathological inclusions, including ; Lewy bodies of Parkinson’s di­sease,neurofi­brillary of Alzheimer’s di­sease, Pick bodies of Pick’s disease.