Methods are described for producing non-immunogenic nanoparticles from protein sources by controlling the pH in a nanoprecipitation process. The nanoparticles that are produced by the disclosed methods range in diameter size from about 100 ran to about 400 nm, with a preferred diameter size of from approximately 100 nm to approximately 300 nm, thereby rendering them non-immunogenic. The invention further discloses methods for producing nanoconjugates that are suitable for a variety of therapeutic, diagnostic and other uses.

A method of refolding proteins expressed in non-mammalian cells present in concentrations of 2.0 g/L or higher is disclosed. The method comprises identifying the thiol pair ratio and the redox buffer strength to achieve conditions under which efficient folding at concentrations of 2.0 g/L or higher is achieved and can be employed over a range of volumes, including commercial scale.

The invention is based on the discovery that the presence of a discordant helix in a protein or peptide is predictive of that protein or peptide's ability to form amyloid. The invention includes methods for detecting discordant helices and methods of screening for compounds that stabilize the -helix of a discordant helix-containing polypeptide. Compounds discovered using these methods are useful for treating or preventing disorders in which amyloid is produced. Such disorders include Alzheimer's disease and prion-associated disorders.

Compounds and methods for refolding of proteins in an aqueous solution. In particular, biocompatible multiblock copolymer surfactants such as poloxamers, meroxapols, poloxamines, or polyols are used to catalyze proper refolding without changing the protein composition, and restore the protein to its native conformation and native biological function. The methods can be practiced both in vivo and in vitro. The biocompatible multiblock copolymer surfactants can be used for renaturation of recombinantly expressed proteins, and for renaturation of proteins that are unfolded due to heat, irradiation, mechanical shearing, electrical shock, frostbite, chemical stress, and other abiotic or biotic stresses.

The invention includes a thioamide-modified peptide, wherein the thioamide modification increases the in vivo half-life of the peptide. The invention further includes methods of treating or preventing a disease or disorder in a subject in need thereof, the method comprising administering to the subject a thioamide-modified peptide of the invention.

The present invention relates to a method for purifying an immunoglobulin, and more particularly, to a method for purifying an immunoglobulin, which comprises: dialyzing and concentrating an immunoglobulin-containing plasma protein fraction II paste; removing thrombotic substances from the dialyzed and concentrated fraction by a purification process using ceramic cation exchange resin; and performing elution while maintaining salt concentration at a constant level to maintain the polymer content of the immunoglobulin at a low level. When the immunoglobulin purification method according to the present invention is used, the efficiency with which impurities and thrombotic substances are removed can be increased and the polymer content of the immunoglobulin can be maintained, and thus a stable immunoglobulin with improved quality can be produced.

In alternative embodiments, provided are methods that are reliable and scalable for making disulfide bond rich peptides and proteins. In alternative embodiments, provided are oxidation refolding methods to produce disulfide bond rich peptides and proteins. In alternative embodiments, methods as provided herein can be used to make any disulfide bond-containing proteins, including but not limited to: three finger neurotoxin peptides (such as for example, rec--Bungarotoxin (rec-Btx), rec--Cobratoxin (rec-CTX), -Bungarotoxin (rec-Btx), rec-MTa, rec-hannalgesin, rec-Mambalgin, rec-Slurp, rec-Pate), antibodies and antibody fragments (such as single chain antibody), extracellular domain of viral membrane proteins, cell surface receptors, other disulfide-bond rich toxin peptides (such as dendrotoxin, conotoxin) and the like.

Disclosed is a method for refolding a protein or peptide that does not contain essential disulfides and that contains at least one free cysteine residue. Also disclosed are polymer IFN- conjugates that have been created by the chemical coupling of polymers such as polyethylene glycol moieties to IFN-, particularly via a free cysteine in the protein. Also disclosed are analogs of bioactive peptides that may be used to create longer acting versions of the peptides, including analogs of glucagon, glucagon-like peptide-1 (GLP-1), GLP-2, Gastric inhibitory peptide (GIP), PYY, exendin, ghrelin, gastrin, amylin, and oxyntomodulin.

Novel polypeptides and methods of making and using the same are described herein. The polypeptides include cross-linking (hydrocarbon stapling) moieties to provide a tether between two amino acid moieties, which constrains the secondary structure of the polypeptide. The polypeptides described herein can be used to treat diseases characterized by excessive or inadequate cellular death.

A method for purifying and renaturating inclusion bodies of scorpion venom protein is provided. The method includes expressing the scorpion venom protein by recombinant Escherichia coli. The C-terminal of the scorpion venom protein has His-tag. The method includes breaking the disulfide bonds in the scorpion venom protein by a denaturating buffer, purifying the denaturated scorpion venom protein with a histidine affinity chromatography column, and renaturating the scorpion venom protein with a renaturation buffer. The renaturation buffer has a pH of 7-9 and includes 50-200 mmol/L Na.sub.2HPO.sub.4, 10-100 mmol/L Tris, 0.1-1 mol/L L-Arg, 1-5 mmol/L EDTA, 0.1-5 mmol/L GSH, 0.05-0.5 mmol/L GSSG, 5-20% (v/v) glycerol, 0.01-5% (v/v) triton X-100. Preparation of the scorpion venom protein by this method has the advantages of simple operation, and good renaturation effect.