Abstract: The invention provides methods, reagents and systems for incorporating non-natural amino acids into proteins, preferably in vivo, using the endogenous protein synthesis machinery of an organism. The incorporated non-natural amino acids contain reactive groups for further chemical reagents, which may serve as a “handle” to enrich the proteins or fragments thereof in a number of uses, such as proteomic analysis, imaging of diseased tissues/cells, etc.

Abstract: The invention provides methods, reagents and systems for incorporating non-natural amino acids into proteins, preferably in vivo, using the endogenous protein synthesis machinery of an organism. The incorporated non-natural amino acids contain reactive groups for further chemical reagents, which may serve as a “handle” to enrich the proteins or fragments thereof in a number of uses, such as proteomic analysis, imaging of diseased tissues/cells, etc.

Abstract: In some embodiments, methods for improving the survival of pancreatic ?-cell progenitors in culture are provided. Such methods may include contacting a population of pancreatic progenitor cells with an amino acid (aa) sequence comprising IKVAV (SEQ ID NO:1). In other embodiments, methods for (i) verifying the establishment of a population of pancreatic progenitor or stem cells and (ii) methods for generating or establishing a population of pancreatic endocrine progenitor cells in vitro are provided.

Abstract: The invention provides a method of incorporating nonstandard amino acids into a protein by utilizing a modified aminoacyl-tRNA synthetase to charge the nonstandard amino acid to a modified tRNA, which forms strict Watson-Crick base-pairing with a codon that normally forms wobble base-pairing with natural tRNAs.

Abstract: The invention provides certain embodiments relating to methods and compositions for incorporating non-natural amino acids into a polypeptide or protein by utilizing a mutant or modified aminoacyl-tRNA synthetase to charge the non-natural amino acid to a the corresponding tRNA. In certain embodiments, the tRNA is also modified such that the complex forms strict Watson-Crick base-pairing with a codon that normally forms wobble base-pairing with unmodified tRNA/aminoacyl-tRNA synthetase pairs.

Abstract: The invention provides a method of incorporating nonstandard amino acids into a protein by utilizing a modified aminoacyl-tRNA synthetase to charge the nonstandard amino acid to a modified tRNA, which forms strict Watson-Crick base-pairing with a codon that normally forms wobble base-pairing with natural tRNAs.

Abstract: Compositions and methods for transport or release of therapeutic and diagnostic agents or metabolites or other analytes from cells, compartments within cells, or through cell layers or barriers are described. The compositions include a membrane barrier transport enhancing agent and are usually administered in combination with an enhancer and/or exposure to stimuli to effect disruption or altered permeability, transport or release. In a preferred embodiment, the compositions include compounds which disrupt endosomal membranes in response to the low pH in the endosomes but which are relatively inactive toward cell membranes, coupled directly or indirectly to a therapeutic or diagnostic agent. Other disruptive agents can also be used, responsive to stimuli and/or enhancers other than pH, such as light, electrical stimuli, electromagnetic stimuli, ultrasound, temperature, or combinations thereof.

Abstract: The invention provides a method of incorporating nonstandard amino acids into a protein by utilizing a modified aminoacyl-tRNA synthetase to charge the nonstandard amino acid to a modified tRNA, which forms strict Watson-Crick base-pairing with a codon that normally forms wobble base-pairing with natural tRNAs.

Abstract: Compositions and methods for transport or release of therapeutic and diagnostic agents or metabolites or other analytes from cells, compartments within cells, or through cell layers or barriers are described. The compositions include a membrane barrier transport enhancing agent and are usually administered in combination with an enhancer and/or exposure to stimuli to effect disruption or altered permeability, transport or release. In a preferred embodiment, the compositions include compounds which disrupt endosomal membranes in response to the low pH in the endosomes but which are relatively inactive toward cell membranes, coupled directly or indirectly to a therapeutic or diagnostic agent. Other disruptive agents can also be used, responsive to stimuli and/or enhancers other than pH, such as light, electrical stimuli, electromagnetic stimuli, ultrasound, temperature, or combinations thereof.

Abstract: The invention provides certain embodiments relating to methods and compositions for incorporating non-natural amino acids into a polypeptide or protein by utilizing a mutant or modified aminoacyl-tRNA synthetase to charge the non-natural amino acid to a the corresponding tRNA. In certain embodiments, the tRNA is also modified such that the complex forms strict Watson-Crick base-pairing with a codon that normally forms wobble base-pairing with unmodified tRNA/aminoacyl-tRNA synthetase pairs.

Abstract: The invention provides certain embodiments relating to methods and compositions for incorporating non-natural amino acids into a polypeptide or protein by utilizing a mutant or modified aminoacyl-tRNA synthetase to charge the non-natural amino acid to a the corresponding tRNA. In certain embodiments, the tRNA is also modified such that the complex forms strict Watson-Crick base-pairing with a codon that normally forms wobble base-pairing with unmodified tRNA/aminoacyl-tRNA synthetase pairs.

Abstract: Compositions and methods for transport or release of therapeutic and diagnostic agents or metabolites or other analytes from cells, compartments within cells, or through cell layers or barriers are described. The compositions include a membrane barrier transport enhancing agent and are usually administered in combination with an enhancer and/or exposure to stimuli to effect disruption or altered permeability, transport or release. In a preferred embodiment, the compositions include compounds which disrupt endosomal membranes in response to the low pH in the endosomes but which are relatively inactive toward cell membranes, coupled directly or indirectly to a therapeutic or diagnostic agent. Other disruptive agents can also be used, responsive to stimuli and/or enhancers other than pH, such as light, electrical stimuli, electromagnetic stimuli, ultrasound, temperature, or combinations thereof.

Abstract: Compositions and methods for transport or release of therapeutic and diagnostic agents or metabolites or other analytes from cells, compartments within cells, or through cell layers or barriers are described. The compositions include a membrane barrier transport enhancing agent and are usually administered in combination with an enhancer and/or exposure to stimuli to effect disruption or altered permeability, transport or release. In a preferred embodiment, the compositions include compounds which disrupt endosomal membranes in response to the low pH in the endosomes but which are relatively inactive toward cell membranes, coupled directly or indirectly to a therapeutic or diagnostic agent. Other disruptive agents can also be used, responsive to stimuli and/or enhancers other than pH, such as light, electrical stimuli, electromagnetic stimuli, ultrasound, temperature, or combinations thereof.

Abstract: The invention provides a method of incorporating nonstandard amino acids into a protein by utilizing a modified aminoacyl-tRNA synthetase to charge the nonstandard amino acid to a modified tRNA, which forms strict Watson-Crick base-pairing with a codon that normally forms wobble base-pairing with natural tRNAs.

Abstract: The invention provides methods, reagents and systems to preferentially mark fast-proliferating cells/tissues (such as cancer), by incorporating non-natural amino acids into proteins, preferably in vivo, using the endogenous protein synthesis machinery of an organism. The incorporated non-natural amino acids contain reactive groups for further chemical reagents, which may serve as a “handle” to for a number of uses, such as imaging of cancer cells, targeting drugs to preferentially kill cancer cells, and proteomic analysis in the context of large scale or high throughput screening for candidate drug leads that affects the proliferation of a target cell, etc.

Abstract: The invention provides methods, systems and reagents for regulating pH-sensitive protein interaction by incorporating non-natural amino acids into the protein (e.g. an antibody, or its functional fragment, derivative, etc.). The invention also relates to specific uses in regulating pH-sensitive binding of antibodies to tumor site, by conferring enhanced tumor-specificity/selectivity. In that embodiment, the non-natural amino acids preferably have desirable side-chain pKa's, such that at below physiological pH (e.g. about pH 6.3-6.5) the non-natural amino acid confer enhanced binding to tumor antigens in acidic environments. Such non-natural amino acids can be incorporated by any suitable means, such as by utilizing a modified aminoacyl-tRNA synthetase to charge the nonstandard amino acid to a modified tRNA, which forms strict Watson-Crick base-pairing with a codon that normally forms wobble base-pairing with natural tRNAs (e.g. the degenerate codon orthogonal system.

Abstract: Compositions and methods for transport or release of therapeutic and diagnostic agents or metabolites or other analytes from cells, compartments within cells, or through cell layers or barriers are described. The compositions include a membrane barrier transport enhancing agent and are usually administered in combination with an enhancer and/or exposure to stimuli to effect disruption or altered permeability, transport or release. In a preferred embodiment, the compositions include compounds which disrupt endosomal membranes in response to the low pH in the endosomes but which are relatively inactive toward cell membranes, coupled directly or indirectly to a therapeutic or diagnostic agent. Other disruptive agents can also be used, responsive to stimuli and/or enhancers other than pH, such as light, electrical stimuli, electromagnetic stimuli, ultrasound, temperature, or combinations thereof.

Abstract: Compositions and methods for transport or release of therapeutic and diagnostic agents or metabolites or other analytes from cells, compartments within cells, or through cell layers or barriers are described. The compositions include a membrane barrier transport enhancing agent and are usually administered in combination with an enhancer and/or exposure to stimuli to effect disruption or altered permeability, transport or release. In a preferred embodiment, the compositions include compounds which disrupt endosomal membranes in response to the low pH in the endosomes but which are relatively inactive toward cell membranes, coupled directly or indirectly to a therapeutic or diagnostic agent. Other disruptive agents can also be used, responsive to stimuli and/or enhancers other than pH, such as light, electrical stimuli, electromagnetic stimuli, ultrasound, temperature, or combinations thereof.

Abstract: The invention provides certain embodiments relating to methods and compositions for incorporating non-natural amino acids into a polypeptide or protein by utilizing a mutant or modified aminoacyl-tRNA synthetase to charge the non-natural amino acid to a the corresponding tRNA. In certain embodiments, the tRNA is also modified such that the complex forms strict Watson-Crick base-pairing with a codon that normally forms wobble base-pairing with unmodified tRNA/aminoacyl-tRNA synthetase pairs.

Abstract: Methods for producing modified polypeptides containing amino acid analogues are disclosed. The invention further provides purified dihydrofolate reductase polypeptides, produced by the methods of the invention, in which the methionine residues have been replaced with homoallylglycine, homoproparglycine, norvaline, norleucine, cis-crotylglycine, trans-crotylglycine, 2-aminoheptanoic acid, 2-butynylglycine and allylglycine.