Abstract: The present invention relates to methods and compositions for modifying peptides, polypeptides and proteins with polymers, especially glyco-mimetic polymers, so as to improve their biological activity or pharmacokinetic properties. The invention further provides methods and uses for such polymer-modified peptides, polypeptides and proteins. The invention is particularly suitable for use in the synthesis of polymer-modified synthetic bioactive proteins (FIG. 1D), and of pharmaceutical compositions that contain such proteins.

Abstract: The present invention concerns methods and compositions for extending the technique of native chemical ligation of a wider range of peptides, polypeptides, other polymers and other molecules via an amide bond (see FIG. 1). The invention further provides methods and uses for such proteins and derivatized proteins. The invention is particularly suitable for use in the synthesis of optionally polymer-modified, synthetic bioactive proteins, and of pharmaceutical compositions that contain such proteins.

Abstract: The invention is directed to methods and compositions for chemical ligation of components comprising a first component having a carboxythioester, and preferable an &agr;-carboxythioester, moiety and a second component having an N-substituted, and preferably an N&agr;-substituted, 2 or 3 carbon chain alkyl or aryl thiol to give a ligation product having an N-substituted amide bond at the ligation site. The reactants of the invention are chemoselective, and the alkyl or aryl thiol moiety is removable from the ligation product. Removal of the alkyl or aryl thiol gives a native amide bond at the ligation site. The methods and compositions of the invention are particularly useful for ligation of peptides and polypeptides. The ligation system of the invention is applicable to a wide variety of molecules, and thus can be exploited to generate peptides, polypeptides and other amino acid containing polymers having a native amide bond at the ligation site.

Abstract: The present invention relates to methods and compositions for modifying peptides, polypeptides and proteins with polymers, especially glyco-mimetic polymers, so as to improve their biological activity or pharmacokinetic properties. The invention further provides methods and uses for such polymer-modified peptides, polypeptides and proteins. The invention is particularly suitable for use in the synthesis of polymer-modified synthetic bioactive proteins (FIG. 1D), and of pharmaceutical compositions that contain such proteins.

Abstract: The present invention concerns methods and compositions for extending the technique of native chemical ligation of a wider range of peptides, polypeptides, other polymers and other molecules via an amide bond (see FIG. 1). The invention further provides methods and uses for such proteins and derivatized proteins. The invention is particularly suitable for use in the synthesis of optionally polymer-modified, synthetic bioactive proteins, and of pharmaceutical compositions that contain such proteins.

Abstract: Synthetic erythropoiesis stimulating proteins are provided. Also provided are methods for synthesizing the proteins. The invention further relates to derivatives of such synthetic erythropoiesis stimulating proteins that are polymer-modified in a defined manner. Methods and uses for such proteins and derivatized proteins are also provided.