Introduction
The C-terminal sequencing, plays a decisive role in the biological function of proteins, is an important structural
and functional part of proteins and polypeptides. In addition, C-terminal modification is also one of the important
post-translational modifications of proteins. The current protein sequencing methods mainly include carboxypeptidase
method, chemical methods, and tandem mass spectrometr, of which MS/MS has been used to sequence peptides and small
proteins for a number of years. This method allows one to isolate the peptide of interest, which makes it possible
to analyze impure samples and unseparated mixtures, such as protein digests. Collision-induced dissociation (CID) of
the selected peptide generates the productions that provide sequence information.
Fig. 1. Principles of ISDMALDI MS. (Ejvind Mort,
et al., 2001)
Our Services
Creative Proteomics relies on the company's existing mass spectrometry platform to develop a
powerful LC-MS/MS system, which is not only suitable for analyzing C-terminal sequences, but also can analyze
N-terminal sequences at the same time. which means the N-terminal sequencing and C-terminal sequencing of protein
could be determined at the same time in one experiment. This analysis will ultimately be used to confirm whether the
recombinant protein is fully expressed, detect whether the recombinant protein is broken during expression, and
whether the N-terminal and C-terminal sequences of the recombinant protein are modified.
Based on the C-terminal sequencing services we provide, our customers have achieved good research results in the
following applications.
- Detect and characterize C-terminal protein processing.
- Directly confirm the C-terminal sequence of native and expressed proteins.
- Identify post-translational proteolytic cleavage.
- Obtain N-terminal partial sequence information of end-capped protein samples.
- Facilitate the design of oligonucleotide probes for gene cloning.
Similar to N-terminal sequencing, mass spectrometry based protein C-terminal sequencing we provide could be achieve
100% coverage of the measured target protein sequence. We first analyze the amino acid sequence information of the
target protein and select specific proteases (Trypsin, Chymotrypsin, Asp-N, Glu-C, Lys-C and Lys-N) to digest the
target protein separately to obtain protein peptides of suitable length, and then analysis them by mass
spectrometry, Then obtain the splicing between peptides while obtaining fragmented peptide.
Fig. 2. Imaged C-terminal sequencing
workflow.
Sample Requirements
- Gel bands, gel spots, and liquid samples can all be used to detecte.
- Liquid samples are required a total of 5-10 μg protein.
- Purity of liquid samples should be as high as possible. For liquid sample <10 μg, please avoid large amounts
of detergent and salt ions, and note the buffer composition and the estimated amount of total proteins when
submitting samples.
Our Technical Advantages
- Peptide coverage up to 100%.
- N-terminal and C-terminal are detected at the same time with less time-consuming.
- High sensitivity.
Applications
Please feel free to contact us If you would like to discuss the best way to
determine the C-terminal sequencing of your protein. At Creative Proteomics, we not only provide
professional protein C-terminal sequencing service projects for global customers, our scientists can also provide
help to design the best solutions according to your specific requirements, and describe them in detailed project
reports, we look forward to with your cooperation.
References
- Bergman T, Cederlund E, Jornvall H, et al. (2003) C-terminal sequence analysis[D]. Current
protocols in protein science. Chapter 11.
