This disclosure describes methods and compositions for protein and peptide sequencing.

An aptamer of nattokinase and method for screening the aptamer are provided, which relate to technical fields of biotechnology. A set of nattokinase nucleic acid aptamers screened by capillary electrophoresis separation technology is: SEQ ID NO:1SEQ ID NO:17. The dissociation constants of the seven aptamers were detected by surface plasmon resonance technology, and the affinity of the seven aptamers was strong, with affinities between 8.7-87 nM. The nucleic acid aptamer of the present disclosure has precise specificity, high affinity, and is convenient for chemical modification, and can be used as an effective molecular recognition tool for the high-sensitive analysis of proteins. it. The recognition technology based on nucleic acid aptamers provides a basis for the development of NK determination and efficient separation and purification.

An aptamer of nattokinase and method for screening the aptamer are provided, which relate to technical fields of biotechnology. A set of nattokinase nucleic acid aptamers screened by capillary electrophoresis separation technology is: SEQ ID NO:1SEQ ID NO:17. The dissociation constants of the seven aptamers were detected by surface plasmon resonance technology, and the affinity of the seven aptamers was strong, with affinities between 8.7-87 nM. The nucleic acid aptamer of the present disclosure has precise specificity, high affinity, and is convenient for chemical modification, and can be used as an effective molecular recognition tool for the high-sensitive analysis of proteins. it. The recognition technology based on nucleic acid aptamers provides a basis for the development of NK determination and efficient separation and purification.

The present invention relates to a method for screening a nucleic acid aptamer comprising: (a) contacting a target molecule immobilized on a solid phase support with a nucleic acid aptamer candidate; (b) collecting the nucleic acid aptamer candidate binding with the target molecule by a capillary electrophoresis; and (c) amplifying the nucleic acid aptamer candidate by PCR.

The present disclosure describes methods, devices, reagents, and kits for the detection of one or more target molecules that may be present in a test sample. In one embodiment, a test sample is contacted with an aptamer that includes a tag and has a specific affinity for a target molecule. An aptamer affinity complex that includes an aptamer bound to its target molecule is allowed to form. If the test sample contains the target molecule, an aptamer affinity complex will generally form in the test sample. The aptamer affinity complex is optionally converted to an aptamer covalent complex that includes an aptamer covalently bound to its target molecule. The aptamer affinity complex (or optional aptamer covalent complex) can then be detected and/or quantified using any of a variety of methods known to one skilled in the art, including using a solid support, using mass spectrometry, and using quantitative polymerase chain reaction (Q-PCR).

The present disclosure describes methods, devices, reagents, and kits for the detection of one or more target molecules that may be present in a test sample. In one embodiment, a test sample is contacted with an aptamer that includes a tag and has a specific affinity for a target molecule. An aptamer affinity complex that includes an aptamer bound to its target molecule is allowed to form. If the test sample contains the target molecule, an aptamer affinity complex will generally form in the test sample. The aptamer affinity complex is optionally converted to an aptamer covalent complex that includes an aptamer covalently bound to its target molecule. The aptamer affinity complex (or optional aptamer covalent complex) can then be detected and/or quantified using any of a variety of methods known to one skilled in the art, including using a solid support, using mass spectrometry, and using quantitative polymerase chain reaction (Q-PCR).

This application relates to molecular biology, and more specifically to a method which uses the molecular recognition between a target molecule ligand and an aptamer, magnetic separation and MS qualitative and quantitative analysis to enable the association between the detection of multi molecules and information of multiple functional groups, and effectively determine the correlation between molecules and functional groups of the body or tissue. This application can easily purify the target molecules by magnetic separation and can effectively obtain the target molecule group based on the high specificity and affinity of the aptamer. In addition, based on the MS detection, this application can effectively perform the qualification and quantification of the multi molecules, achieving the secondary molecular detection and improving the detection accuracy. The simultaneous qualification and quantification of multi molecules can not only accurately reflect the relationship among molecules, but also reveal the interrelationship among body functions, playing a significant role in the proteomics and genomics research and clinical molecular detection.

Provided is a nucleic acid aptamer screening method based on the localized surface plasmon resonance technology, falling within the fields of molecular recognition and nucleic acid aptamer screening. The method screens out a nucleic acid aptamer that can specifically bind to a target mainly with the aid of a localized surface plasmon resonance personal molecular interaction analyzer. The screening method comprises: taking a nano-gold chip as a medium, fixing the target on the medium, and then carrying out the visualized screening of the nucleic acid aptamer by taking the nucleic acid aptamer as a recognition element. With the aid of the LSPR-SELEX technique, the method does not require any marker during the process of detection by using a solid chip, and maintains the spatial structure and biological activity of the nucleic acid aptamer at the maximum. Compared to the traditional nucleic acid aptamer screening method, the LSPR-SELEX sensing technology is simple to operate and has a high sensitivity, and is less time-consuming (15 min) and has a quick response speed. The greatest advantage lies in that the interaction data is represented on-line in real time, and the affinity between molecules of each round can be acquired quickly and accurately.

Provided is a nucleic acid aptamer screening method based on the localized surface plasmon resonance technology, falling within the fields of molecular recognition and nucleic acid aptamer screening. The method screens out a nucleic acid aptamer that can specifically bind to a target mainly with the aid of a localized surface plasmon resonance personal molecular interaction analyzer. The screening method comprises: taking a nano-gold chip as a medium, fixing the target on the medium, and then carrying out the visualized screening of the nucleic acid aptamer by taking the nucleic acid aptamer as a recognition element. With the aid of the LSPR-SELEX technique, the method does not require any marker during the process of detection by using a solid chip, and maintains the spatial structure and biological activity of the nucleic acid aptamer at the maximum. Compared to the traditional nucleic acid aptamer screening method, the LSPR-SELEX sensing technology is simple to operate and has a high sensitivity, and is less time-consuming (15 min) and has a quick response speed. The greatest advantage lies in that the interaction data is represented on-line in real time, and the affinity between molecules of each round can be acquired quickly and accurately.

Disclosed is a method of quantitatively analyzing a target protein population in a sample to be analyzed, the method including (a) treating a sample to be analyzed with an aptamer library specific to a target protein population present in the sample so as to form complexes between target proteins and aptamers binding specifically thereto, thereby forming a target protein-aptamer complex population, (b) isolating the complex population from unbound aptamers, and (c) analyzing the sequence of each aptamer of the complex population through a next-generation sequencing process so as to quantify each aptamer of the complex population, thereby quantifying each target protein in the complex population. The method of the present invention can be very useful in collectively quantifying proteins in an analytical sample.