The invention provides improved methods of conjugating an agent to a thiol moiety in a protein that contains at least one disulfide bond and at least one trisulfide bond. Exemplary embodiments include the production of antibody drug conjugates substantially free of impurities created in the presence of reactive sulfide moieties in the production processes.

Disclosed herein are amantadine binding polypeptides, fusion proteins thereof, and uses of such polypeptides and fusion proteins.

The present invention provides a new type of alpha-helix nucleating cross-link (“staple”) formed by olefin metathesis of a proline derivative with an alkenyl side chain and another amino acid derivative with an alkenyl side chain. The proline derivatives as described herein have been found to be strong nucleators of alpha-helix formation. The invention also provides moieties for shielding the free amide N—H's at the N-terminus of an alpha-helix, thereby further stabilizing the helix. The proline derivatives, precursors prior to cross-linking, and the cross-linked peptides are provided as well as methods of using and preparing these compounds and peptides.

The present invention provides a new type of alpha-helix nucleating cross-link (“staple”) formed by olefin metathesis of a proline derivative with an alkenyl side chain and another amino acid derivative with an alkenyl side chain. The proline derivatives as described herein have been found to be strong nucleators of alpha-helix formation. The invention also provides moieties for shielding the free amide N—H's at the N-terminus of an alpha-helix, thereby further stabilizing the helix. The proline derivatives, precursors prior to cross-linking, and the cross-linked peptides are provided as well as methods of using and preparing these compounds and peptides.

The present disclosure relates to a method for modifying or marking an amino group in a molecule, wherein the amino group in the molecule is modified or marked with zolinium(s) shown in the following formula 1, wherein the molecule comprises amino acid ester, aminoamide, or peptide/protein. The method has advantages of economy and site selectivity, and has huge potential application value in the field such as pharmaceutical molecular synthesis, probe molecule and diagnostic marker reagent development.

The present disclosure relates to a method for modifying or marking an amino group in a molecule, wherein the amino group in the molecule is modified or marked with zolinium(s) shown in the following formula 1, wherein the molecule comprises amino acid ester, aminoamide, or peptide/protein. The method has advantages of economy and site selectivity, and has huge potential application value in the field such as pharmaceutical molecular synthesis, probe molecule and diagnostic marker reagent development.

A method for producing a cyclic peptide, including the following step (1) and step (2):

(1) a step of cyclizing a linear peptide; and

(2) a step of obtaining a cyclic peptide by adding a poor solvent to a mixture of the cyclic peptide and multimeric impurity, which mixture is obtained in the above-mentioned step, and filtering off the multimeric impurity as an insoluble material can efficiently remove multimeric impurity by-produced during a cyclization reaction, improve the purity of the obtained cyclic peptide, and reduce a burden on the purification step.

Provided herein are methods for refolding denatured protein (e.g., from inclusion bodies) that do not require the use of a denaturing agent. Exemplary methods use a high pH for solubilizing denatured protein, followed by a decrease in pH for refolding the proteins.

A peptide complex including: a peptide; and a cell-membrane-permeability-imparting group introduced into the peptide, wherein the cell-membrane-permeability-imparting group includes a dendritic structure including four or more branches, and at least four branches of the four or more branches include basic functional groups at ends thereof.

A peptide complex including: a peptide; and a cell-membrane-permeability-imparting group introduced into the peptide, wherein the cell-membrane-permeability-imparting group includes a dendritic structure including four or more branches, and at least four branches of the four or more branches include basic functional groups at ends thereof.