Scaling Proteome-Wide Reactions of Activity-Based Probes.

ABSTRACT: Unified analysis of complex reactions of an activity-based probe with proteins in a proteome remains an unsolved challenge. We propose a power expression, rate = kobs[Probe]?, for scaling the progress of proteome-wide reactions and use the scaling factor (0 ? ? ? 1) as an apparent, partial order with respect to the probe to measure the "enzyme-likeness" for a protein in reaction acceleration. Thus, ? reports the intrinsic reactivity of the protein with the probe. When ? = 0, the involved protein expedites the reaction to the maximal degree; when ? = 1, the protein reacts with the probe via an unaccelerated, bimolecular reaction. The selectivity (?) of the probe reacting with two proteins is calculated as a ratio of conversion factors (kobs values) for corresponding power equations. A combination of ? and ? provides a tiered system for quantitatively assessing the probe efficacy; an ideal probe exhibits high reactivity with its protein targets (low in ?) and is highly selective (high in ?) in forming the probe-protein adducts. The scaling analysis was demonstrated using proteome-wide reactions of HT-29 cell lysates with a model probe of threonine ?-lactone.

SUBMITTER: Li S 

PROVIDER: S-EPMC6368408 | biostudies-literature | 2017 Jun

REPOSITORIES: biostudies-literature