Abstract: Computer-implementable methods consistent with the present teachings can be used in the design of selective- and multiple-reaction monitoring experiments for the identification of proteins and peptides of interest. By determining candidate parent-daughter ion transition pairs and scoring the pairs based on their ability to be detected experimental design time can be reduced and with a more focused list of transition pairs more experiments can be run successfully in a given period of time.

Abstract: The present teachings provide methods for the development of a mass spectrometric based assay for a protein in a sample using parent-daughter ion transition monitoring (PDITM). In various aspects, the present teachings provide methods for developing a mass spectrometric based assay for a protein in a sample without the use of a standard for the protein. In various embodiments, the sample comprises proteolytic fragments of a protein which is present in low abundance in the physiological fluid from which it is derived.

Abstract: In various aspects, the present teachings provide systems, methods, assays and kits for the absolute quantitation of protein expression. In various aspects, the present teachings provide methods of determining the concentration of one or more proteins of interest in one or more samples of interest. In various aspects, the present teachings provide methods of determining the absolute concentration of one or more isoforms of a protein using standard samples of signature protein fragments and parent-daughter ion transition monitoring (PDITM). In various embodiments, the absolute concentration of multiple isoforms of a biomolecule in a sample, multiple proteins in a biological process, a combination of multiple samples, or combinations thereof, can be determined in a multiplex fashion using the present teachings. In various aspects, provided are methods of assessing the response of a biological system to a chemical agent.

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, and of pharmaceutical compositions that contain such proteins.

Abstract: The present invention concerns methods and compositions for extending the technique of native chemical ligation to permit the ligation of a wider range of peptides, polypeptides, other polymers and other molecules via an amide bond. 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: In various aspects, the present teachings provide systems, methods, assays and kits for the absolute quantitation of protein expression. In various aspects, the present teachings provide methods of determining the concentration of one or more proteins of interest in one or more samples of interest. In various aspects, the present teachings provide methods of determining the absolute concentration of one or more isoforms of a protein using standard samples of signature protein fragments and parent-daughter ion transition monitoring (PDITM). In various embodiments, the absolute concentration of multiple isoforms of a biomolecule in a sample, multiple proteins in a biological process, a combination of multiple samples, or combinations thereof, can be determined in a multiplex fashion using the present teachings. In various aspects, provided are methods of assessing the response of a biological system to a chemical agent.