photoaffinityn.
/ˌfəʊtəʊəˈfɪnᵻti/, U.S. /ˌfoʊdoʊəˈfɪnᵻdi/ Biochemistry.
attributive. Designating or relating to a technique of labelling large molecules (esp. proteins) at specific sites by means of smaller molecules which initially form loose complexes at the active sites and are then photochemically converted in situ to reactive forms which immediately bond more permanently.
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the world > life > biology > laboratory analysis > processes > [adjective] > labelling
labelled1935
tagged1945
radiolabelled1949
radio-tagged1949
pulse-labelled1962
photoaffinity1970
1970 H. Kiefer et al. in Proc. National Acad. Sci. U.S.A. 67 1688 The usual affinity-labeling reagent has the structure R—X, where R is the portion of the molecule that binds specifically and reversibly to the active site under study, and X is a chemically reactive group, such as diazonium or haloacyl... In photo-affinity labeling, a reagent R—P is used, where P is a group that is ordinarily unreactive, but which can be converted by photolysis to an exceedingly reactive intermediate P*. Those molecules of R—P that are reversibly bound to the active sites react instantaneously upon conversion to R—P* before they can dissociate from the site.
1976 Nature 29 Apr. 802/1 Without irradiation the photoaffinity label reversibly inhibited the potassium conductance..whereas the sodium conductance was not affected.
1990 EMBO Jrnl. 9 4111/1 A photoaffinity cross-linking agent was coupled to the substrate phosphate on which RNase P acts and used to map nucleotides in the vicinity of the catalytic site of this ribozyme.
This entry has been updated (OED Third Edition, March 2006; most recently modified version published online March 2022).
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n.1970