The present invention relates to a method of formation of a sulphur bridge between tryptophan and cysteine in solid phase peptide synthesis under iodine treatment. The invention also relates to the resulting compounds of the method and their respective use.

The present invention provides a method for sequencing a protein/polypeptide based on Aerolysin nanopores to achieve specific discrimination of natural amino acids and post-translational modifications thereof and accurate acquisition of a sequence of a single-molecule protein, the method including the following steps: (1) unfolding of the protein; (2) terminus labeling of protein sequencing; (3) protein charge screening; (4) unfolding of a tertiary structure of the polypeptides; (5) orthogonal identification of amino acids; (6) confined perturbation-assisted identification of amino acids; and (7) single-molecule protein sequencing. The present invention aims at sensitive detection of sequence information about 20 amino acids and establishes an innovative method for accurately determining sequences of the amino acids and post-translational modifications of a single protein molecule.

Dithioamine reducing agents useful for the reduction of disulfide bonds. The reducing agents of this invention are useful, for example, to reduce disulfide bonds, particularly in proteins, or to prevent the formation of disulfide bonds, particularly in proteins and other biological molecules. Reducing agents of this invention can be employed to regulate protein function in proteins in which a sulfhydryl group is associated with biological activity. Reducing agents of this invention can prevent inactivation of a given protein or enhance activation of a given protein or other biological molecule in vitro and/or in vivo. Reducing agents of this invention can prevent or reduce oxidation of cysteine residues in proteins and prevent the formation of reduced activity protein dimers (or other oligomers). Reducing agents of this invention are useful and suitable for application in a variety of biological applications, particularly as research and synthetic reagents. The invention provides S-acylated dithioamines which can be selectively activated reducing agents by removal of the S-acyl groups enzymatically or chemically. The invention further provides dithiane precursors of thioamino reducing agents. The invention provides dithioamine reducing agents, S-acylated dithioamines and dithianes which are immobilized on surfaces, including among others, glass, quartz, microparticles, nanoparticles and resins.

Dithioamine reducing agents useful for the reduction of disulfide bonds. The reducing agents of this invention are useful, for example, to reduce disulfide bonds, particularly in proteins, or to prevent the formation of disulfide bonds, particularly in proteins and other biological molecules. Reducing agents of this invention can be employed to regulate protein function in proteins in which a sulfhydryl group is associated with biological activity. Reducing agents of this invention can prevent inactivation of a given protein or enhance activation of a given protein or other biological molecule in vitro and/or in vivo. Reducing agents of this invention can prevent or reduce oxidation of cysteine residues in proteins and prevent the formation of reduced activity protein dimers (or other oligomers). Reducing agents of this invention are useful and suitable for application in a variety of biological applications, particularly as research and synthetic reagents. The invention provides S-acylated dithioamines which can be selectively activated reducing agents by removal of the S-acyl groups enzymatically or chemically. The invention further provides dithiane precursors of thioamino reducing agents. The invention provides dithioamine reducing agents, S-acylated dithioamines and dithianes which are immobilized on surfaces, including among others, glass, quartz, microparticles, nanoparticles and resins.

Disclosed herein, in some aspects, are synthetic secretion signal peptides. Also disclosed are nucleic acid molecules encoding such signal peptides, in some cases operably linked to a protein coding sequence, as well as cells comprising such nucleic acid molecules. Further disclosed are methods for secreting a polypeptide comprising expressing in a cell a signal peptide of the disclosure linked to the polypeptide. Certain aspects include proteins (e.g., human milk proteins) produced by such methods, as well as compositions comprising such proteins.

The present invention provides methods for producing peptide compounds. The inventors have found that a cyclic peptide compound can be produced efficiently by linking the N-terminal amino acid residue and the C-terminal amino acid residue of a peptide compound in a solvent containing one or more selected from the group consisting of water-immiscible solvents, water-soluble alkyl nitriles, and water-soluble ethers.

The present invention relates to an in vitro method for production of heterodimeric proteins.

The present disclosure pertains to compositions comprising anti-VEGF and methods for producing such compositions in chemically defined media and controlling amounts of certain oxidized aflibercept variants.

The present disclosure pertains to compositions comprising anti-VEGF and methods for producing such compositions in chemically defined media and controlling amounts of certain oxidized aflibercept variants.

A composition of renaturation buffer solution for dimeric proteins and method for using it. The renaturation buffer solution comprises buffer, oxido shuffling system, primary additives, chelating agent and polysorbate compound. The method for renaturation of dimeric proteins includes solubilization of target proteins using a solubilization buffer, solution dilution of the renatured target protein using a renaturation buffer containing polysorbate compound(s), concentrating of the target protein solution to a concentration approaching saturation. A method of applying renature denatured or misfolded proteins to become correctly folded and bioactive. A method of proper renaturation of recombinant proteins that have been expressed using translation vehicles (e.g., bacteria, insects, etc.) and proteins damaged by mechanical shearing, chemical stresses, and other stresses.