Patent ID: 7393828

Claim:
A protein modified with a pH-responsive or light-responsive compound of the general formula Q-C or P—C, wherein Q is a chargeable group selected from the group consisting of Q 1 , Q 2 , and Q 3 as depicted in the following, wherein R 1 , R 2 , R 3 ═H, methyl (Me), ethyl (Et), propyl (Pr), isopropyl (iPr), phenyl (Ph), benzyl (Bn), wherein P is a photocleavable chargeable group selected from the group consisting of P 1 , P 2 , P 3 , P 4 , P 5 , P 6 , P 7 and P 8 as depicted in the following, wherein, R 1 , R 2 ═H, Me, Et, Pr, iPr, Ph, Bn and R 3 ═H, OMe, and wherein C is a coupling group selected from the group consisting of C 1 , C 2 , C 3 , C 4 , C 5 and C 6 as depicted in the following, wherein X═Br, I and wherein the protein is a mechanosensitive channel of large conductance (MscL), and wherein the compound is attached via coupling group C to a cysteine residue of the protein, located in a region that corresponds to amino acid residues 1-14, residues 15-45, residues 46-75 or residues 76-100 of the MscL protein of E. coli.