| abstract |
A reagent having the general formula of General Formula I:n nwherein group Z comprises a spacer selected from an aliphatic chain up to about 6 carbonnequivalents in length, an unbranched aliphatic chain of from about 6 to 18 carbonnequivalents in length with at least one of an intermediate amide and a disulfide moiety, andna polyethylene glycol chain of from about 3 to 12 carbon equivalents in length; whereinngroup R is an electrophilic or nucleophilic moiety suitable for reaction of the reagent withna biologically active species; and wherein group Q is one of nothing at all, an amide, anmethyl amide, a methylene, an ether, a thioether, a methyl ether, and a methyl thioethernmoiety. Also, a conjugate, a bioconjugate and a method of conjugating. |