Protein Sequencer

Once samples are applied to the membrane, analysis using the protein sequencer is almost completely automatic and requires no additional time or trouble. By using protein sequencer data to supplement information obtained with a mass spectrometer, which is currently the most common method, even more reliable information can be obtained about amino acid sequences in proteins and peptides.

Biopharmaceuticals are drugs produced using living organisms,such as microbes or cell cultures. Unlike small-molecule drugs manufactured by chemical synthesis, incubation during biopharmaceutical manufacturing can be impacted by a variety of factors, so even slight changes can affect the final products. Therefore, to maintain the safety and efficacy of biopharmaceuticals, the manufacturing processes must be strictly controlled. N-terminal amino acid sequences are typically analyzed for characterization analysis, which is one such quality control technique. Using a protein sequencer for that analysis can ensure highly reliable amino acid sequencing results. Therefore, a protein sequencer is not only useful for research and development applications but can also be very useful for quality control applications.

This article introduces an example of identification of a PTH-modified cysteine (phenylthiohydantoin derivative of reductively-alkylated cysteine) by analyzing reductively-alkylated peptides/proteins with PPSQ™ -50A series protein sequencer systems (isocratic system and gradient system).

The PPSQ-50A protein sequencer system enables easy and accurate identification of N-terminal amino acid sequences and can also identify cysteine and cystine. Because cysteine and cystine are degraded more markedly than other amino acids during Edman degradation, a certain sample amount is necessary in order to determine the elution position with a protein sequencer. In the future, this Shimadzu protein sequencer system is expected to be an effective tool for structural analysis in proteomic analysis and evaluation of these substances as synthetic intermediates before they form disulfide bonds during peptide synthesis.

Although the improved sequencing protocol caused a slight increase in background noise in chromatograms due to the products of Edman degradation, this increase had no impact on identification of PTH-amino acids, and the results confirmed an improved percent yield of basic amino acids. Based on the above findings, the improved protocol seems effective at improving basic amino acid yields from Edman degradation.

This article introduces amino acid sequencing using a trace protein of IgG (derived from mouse serum). The PPSQ-51A/53A Gradient System is an indispensable instrument for proteome analysis for its reliable and easy identification of amino acid sequences.

The PPSQ-50A isocratic system enables easy and accurate identification of N-terminal sequences and can also identify modified amino acids. Thus, this can be considered an effective system as a tool for identification of post-translational modifications in protein analyses.

LabSolutions PPSQ software provides compliance with FDA 21 CFR Part 11 guidelines and enables compliance with the security, user management, and audit trail requirements specified by FDA 21 CFR Part 11.