Ammonium cation detergents comprising a quaternary or tertiary ammonium cation can be used as detergents to denature proteins and are particularly useful in denaturing glycoproteins or glycopeptides prior to enzymatic deglycosylation. Ammonium cation detergents with sulfate or sulfonate anions are particularly useful.

Arylfluorosulfate compounds derived from anticancer drugs are disclosed herein, which exhibit improved anti-cancer cell proliferation activities compared to their phenolic drug precursors. Among these compounds, the fluorosulfate derivative of fulvestrant showed significantly enhanced activity to down-regulate estrogen receptor (ER) expression in ER.sup.+ breast cancer cell line MCF-7, and oral availability in vivo; the fluorosulfate derivative of combretastatin A4 exhibited a 70-fold increase in potency in the drug resistant colon cancer cell line HT-29; and the fluorosulfate derivative of ABT-751 showed enhanced activity relative to ABT-751.

The present invention provides a method for producing a multimeric protein composed of a monomeric protein, wherein the monomeric protein is obtained by fusing a protein having an immunoglobulin fold structure to a protein that can serve as a subunit structure, the method including the steps of: (A) preparing the monomeric protein having an insoluble granular form in cells of a microorganism; (B) solubilizing the monomeric protein prepared in step (A) with an aqueous solution containing lauroyl-L-Glu; (C) diluting a solution obtained in step (B) in a buffer containing arginine hydrochloride to lower a concentration of lauroyl-L-Glu; and (D) replacing a solvent of a solution obtained in step (C) with a buffer using gel filtration chromatography or the like.

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.

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 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 of processing or fractionating a sample comprising proteins, polypeptides and/or peptides, said method comprising (a) changing the physicochemical conditions of said sample; and (b) performing one or both of the following (i) and (ii): (i) adding solid particulate matter to said sample; and (ii) performing said method in a vessel with a rough surface; wherein steps (a) and (b) can be effected concomitantly or in any order; and wherein said processing or fractionating yields one or more first fractions of proteins, polypeptides and/or peptides as a precipitate on said particulate matter and/or said inhomogeneous surface, and a second fraction of proteins, polypeptides and/or peptides remaining in a supernatant.

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.

Provided herein, in some aspects, are methods of developing a biological therapeutic product. The methods can be used to formulate a biological therapeutic agent or screen biological therapeutic agents.

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.