Disclosed in the present application is a method for constructing an antigen-specific binding polypeptide gene display vector. The method comprises processing by using a restriction endonuclease that specifically recognizes a restriction site to obtain four nucleic acid fragments having specific sticky ends, and then enabling the nucleic acid fragments to directionally ligate. Further disclosed in the present application are an antigen-specific binding polypeptide gene display vector produced according to the method and a bacterial library. The method described in the present application can be used for effectively screening antigen-specific antigen-binding polypeptides or fragments thereof.

The invention relates to the field of biomedicine, and an anti-pertussis toxin (PT) single domain antibody and derivative protein thereof are disclosed. Specifically, a pertussis toxin-binding protein and use thereof are disclosed.

The present invention revealed that translating an mRNA that encodes a peptide containing an unnatural amino acid in a translation system that contains a ribosome containing an engineered L31 protein can increase the amount of the translated peptide. Furthermore, the invention revealed that by using this ribosome, the relative amount of by-products can also be reduced. An engineered L31 protein of the present invention has an amino acid sequence with deletion of 6 or more amino acid residues from the C terminus in the amino acid sequence of the wild-type Escherichia coli L31 protein.

The present invention provides a heat-resistant DNA polymerase mutant with high amplification activity. Particularly, the present invention uses protein directed evolution technology to construct a random mutation library for the polymerase active domain of Taq enzyme, and gradually adds screening pressure, so that unsuitable mutations will be eliminated naturally, and mutations with dominant traits will gradually accumulate. Finally, a series of amino acid sites and their mutations that are critical to Taq enzyme amplification and polymerization performance will be selected, and a Taq enzyme mutant with high amplification activity will be obtained.

Methods, systems and related compositions are provided to perform single-cell marking of a nucleic acid and/or protein in a sample based on in-cell or in-organelle barcoding of nucleic acid and/or protein complexes of the cell or organelle; the methods and systems herein described are configured to provide in-cell or in-organelle single-cell marked nucleic acid and/or protein complexes comprising a single-cell, cell-specific, or a single-cell organelle-specific marker.

Methods, systems and related compositions are provided to perform single-cell marking of a nucleic acid and/or protein in a sample based on in-cell or in-organelle barcoding of nucleic acid and/or protein complexes of the cell or organelle; the methods and systems herein described are configured to provide in-cell or in-organelle single-cell marked nucleic acid and/or protein complexes comprising a single-cell, cell-specific, or a single-cell organelle-specific marker.

The present invention relates to a composition for screening various signal peptides to select specific ones that allow efficient secretion of a target protein to out of host cells. The present invention also relates to a method for selecting specific signal peptides that express a target protein in host cells and efficiently secrete the target protein to out of the host cells. The use of the composition and/or method according to the present invention enables ultrafast selection of optimal signal peptides for a target protein through barcoding sequences corresponding to the signal peptides, leading to the maximization of the production yield of the recombinant protein.

A protein scaffold based on a consensus sequence of fibronectin type III (FN3) proteins, such as the tenth FN3 repeat from human fibronectin (human Tenascin), including isolated nucleic acids that encode a protein scaffold, vectors, host cells, and methods of making and using thereof have applications in diagnostic and/or therapeutic compositions, methods and devices. In particular, protein scaffold molecules binding to IgG have been identified as useful for diagnostic and/or therapeutic applications.

Disclosed herein are methods and compositions for generating a repertoire of recombinant fusion polypeptides from immune cells, and uses thereof.

Disclosed herein are methods and compositions for generating a repertoire of recombinant fusion polypeptides from immune cells, and uses thereof.