Polypeptide immobilization

A disulfide of formula (V):

• J—S—S—L—Q—T (V),
• wherein —L— is —(Ax—By—Ez—D)w—;
• each A, B, E and D are individually C(RARA′)—, —C(RBRB′)—, —C(RERE′)—, and —C(RDRD′)—, respectively;
• each RA, RB, RE and RD is selected from the group consisting of H, alkyl, alkenyl, alkynyl, aryl and heterocyclic radical, or any two of RA, RB, RE and RD together form a bond, or any two of RA, RB, RE and RD together with the atoms to which they are bonded form a ring;
• each RA′, RB′, RE′ and RD′ is selected from the group consisting of H, alkyl, alkenyl, alkynyl, aryl and heterocyclic radical, or any two of RA′, RB′, RE′ and RD′ together form a bond, or any two RA′, RE′, RB′ and RD′ together with the atoms to which they are bonded form a ring;
• each x, y and z are individually either 0 or 1;
• w is 1 to 5;
• —Q— is selected from the group consisting of
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• —T is a reactant ligand;
• —J is selected from the group consisting of H, halogen, R, —OR, —NRR′, —C(O)R, and —C(O)OR;
• R is selected from the group consisting of alkyl, alkenyl, alkynyl, aryl and heterocyclic radical;
• and
• R′ is selected from the group consisting of H, alkyl, alkenyl, alkynyl, aryl and heterocyclic radical;
• wherein the disulfide does not selectively bind avidin or streptavidin.

A substrate, comprising:

• (i) a surface comprising gold, and
• (ii) a plurality of moieties, on at least a portion of said surface,
• wherein said moieties are alkanethiolate moieties of formula (VI ):
• Surf-S—L—Q—T (VII),
• wherein —L— is —(Ax—By—Ez—D)w—;
• each A, B, E and D are individually C(RARA′)—, —C(RBRB′)—, —C(RERE′)—, and —C(RDRD′)—, respectively;
• each RA, RB, RE and RD Is selected from the group consisting of H, alkyl, alkenyl, alkynyl, aryl and heterocyclic radical, or any two of RA, RB, RE and RD together form a bond, or any two of RA, RB, RE and RD together with the atoms to which they are bonded form a ring;
• each RA′, RB′, RE′ and RD′ is selected from the group consisting of H, alkyl, alkenyl, alkynyl, aryl and heterocyclic radical, or any two of RA′, RB′, RE′ and RD′ together form a bond, or any two RA′, RE′, RB′ and RD′ together with the atoms to which they are bonded form a ring;
• each x, y and z are individually either 0 or 1;
• w is 1 to 5;
• —Q— is selected from the group consisting of
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• —T comprises a reactant ligand;
• and
• Surf designates where the moieties attach to said surface.

A protein chip, comprising:

• a substrate;
• and
• a reaction product of a reactant ligand and a fusion polypeptide, on said substrate;
• wherein said fusion polypeptide comprises a capture polypeptide moiety corresponding to said reactant ligand.

A fusion of a capture polypeptide and a display moiety,

• wherein the display moiety does not consist of GST, His tag, lacZ, trpE, maltose binding protein, thioredoxin, or Fc region of an immunoglobulin;
• and
• a corresponding reactant ligand of the capture polypeptide is a moiety of formula (III):
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A method of immobilizing a display moiety on a surface, comprising:

• reacting a capture polypeptide moiety with a corresponding reactant ligand to form a covalent bond;
• wherein the capture polypeptide moiety is a fusion with the display moiety;
• and
• wherein the reactant ligand is attached to the surface.