Hindered linking agents and methods

Abstract

Novel compounds and methods for the formation of disulfide linkages are presented. The novel compounds employed are substituted 2-iminothiolane hydrohalide linking agents of the following formula (I): ##STR1## wherein, X is halogen; R.sub.1 is COOR.sub.5 ; halogen; nitro; unsubstituted or halogenated C.sub.1-8 alkyl; unsubstituted or halogenated C.sub.1-8 alkoxy; unsubstituted or halogenated C.sub.2-8 alkenyl; unsubstituted or halogenated C.sub.2-8 alkynyl; unsubstituted C.sub.3-8 cycloalkyl; unsubstituted aryl; aryl substituted with 1 to 3 substituents selected from halogen, amino, unsubstituted or halogenated C.sub.1-8 alkyl, or unsubstituted or halogenated C.sub.1-8 alkoxy; unsubstituted heterocycle; or heterocycle substituted with 1 to 3 substituents selected from amino, halogen, unsubstituted or halogenated C.sub.1-8 alkyl, or unsubstituted or halogenated C.sub.1-8 alkoxy; each of R.sub.2, R.sub.3 and R.sub.4 is independently hydrogen or selected from the values of R.sub.1 ; or R.sub.1 and R.sub.2 together form a C.sub.2-5 alkylene bridge, unsubstituted or substituted with one to five C.sub.1-4 alkyl groups; or R.sub.1 or R.sub.2 together with R.sub.3 form a C.sub.1-5 alkylene bridge, unsubstituted or substituted with one to five C.sub.1-4 alkyl groups; and R.sub.5 is hydrogen or C.sub.1-8 alkyl. Also included in the invention are methods for covalently linking two species, which methods comprise reacting one or both of the two species with a crosslinking agent of the above formula (I) and mixing the two species together. The resulting conjugated species containing the linking group are also included in the invention. Further included in the invention is the use of a quenching agent which allows direct measurement of the reaction of 2-iminothiolanes with nucleophilic groups.

Dependencies are inferred from the claim text.