Disclosed herein are compositions, methods, and kits for a cell incorporating unnatural amino acids into an unnatural polypeptide. Also disclosed herein are compositions, methods, and kits for increasing activity and yield of the unnatural polypeptide synthesized by the cell.

Disclosed herein are methods, compositions and kits for the synthesis of proteins which comprises unnatural amino acids that utilize a mutant tRNA.

Obtained is: a method for efficiently producing a polypeptide containing a non-canonical amino acid; a method for incorporating a non-canonical amino acid into a polypeptide; a method for producing tRNA bound to a non-canonical amino acid; a a non-canonical amino acid incorporation system; a material for use in these methods; or the like. Used is a method for producing a polypeptide containing a non-canonical amino acid, comprising: a step of bringing PylRS from an organism belonging to the order Methanomassiliicoccales or Thermoplasmatales into contact with the non-canonical amino acid; and an incorporation step selected from step (a) of incorporating the non-canonical amino acid into the polypeptide with higher efficiency than in a case of using a cell-free protein synthesis system with PylRS of Methanosarcina mazei (MmPylRS) or step (b) of incorporating the non-canonical amino acid into the polypeptide with higher efficiency than in a case of using an Escherichia coli protein synthesis system with a vector carrying a gene for the PylRS under regulation by a glmS promoter or a case of using an Escherichia coli protein synthesis system with a vector carrying a gene for the PylRS under regulation by a glnS promoter. Alternatively, used is a a non-canonical amino acid incorporation system containing highly concentrated PylRS from an organism belonging to the order Methanomassiliicoccales or Thermoplasmatales.

Disclosed herein are methods, compositions and kits for the synthesis of proteins which comprises unnatural amino acids that utilize a mutant tRNA.

Provided herein are, inter alia, non-toxic, bioreactive unnatural amino acids and methods of using same.

The invention relates to a polypeptide comprising an amino acid having a bicyclo[6.1.0]non-4-yn-9-ylmethanol (BCN) group, particularly when said BCN group is present as: a residue of a lysine amino acid. The invention also relates to a method of producing a polypeptide comprising a BCN group, said method comprising genetically incorporating an amino acid comprising a BCN group into a polypeptide. The invention also relates to an amino acid comprising bicyclo[6.1.0]non-4-yn-9-ylmethanol (BCN), particularly and amino acid which is bicyclo[6.1.0]non-4-yn-9-ylmethanol (BCN) lysine. In addition the invention relates to a Py1RS tRNA synthetase comprising the mutations Y271M, L274G and C313A.

The present invention relates to a mutated virus. Said virus can be an influenza virus of human or other animal origin. The present invention also relates to a method for preparing the mutated virus, the method comprising introducing UAG codons into positions upstream of the stop codons per se of one or more genes of a viral genome by reverse genetic techniques. The present invention further relates to uses of the mutated virus, for example, as a live attenuated vaccine, or in replication of controllable and safe virus models, and the like.

Disclosed herein are methods, compositions and kits for the synthesis of proteins which comprises unnatural amino acids that utilize a mutant tRNA.

The invention relates to archaeal pyrrolysyl tRNA synthetases lacking a nuclear localization signal and/or comprising a nuclear export signal. The invention also relates to polynucleotides encoding said pyrrolysyl tRNA synthetases, eukaryotic cells comprising said polynucleotide and tRNA acylated by the pyrrolysyl tRNA synthetase or a polynucleotide encoding such tRNA, methods utilizing said cells for preparing polypeptides comprising unnatural amino acid residues, and kits useful in said methods.

Provided herein are compositions and methods for generating polypeptides using non-natural amino acids (nnAAs) and genetic machinery, wherein the modified polypeptides, such as therapeutic polypeptides, bind to albumin, such as serum albumin. Methods of substituting a non-natural amino acid in a first polypeptide to obtain a modified polypeptide, the nnAA in some instances comprising an albumin targeting group, are disclosed, as are methods for making populations of such modified polypeptides. A therapeutic polypeptide, interleukin-1 receptor antagonist (IL-1RA) is exemplified using the disclosed methods.