In order to assess the biological function of proteins and their modifications for understanding signaling mechanisms within cells as well as specific biomarkers to disease, it is important to study the change of proteome under different experimental conditions. Can protein quantification be used for identifying protein?

SILAC-based quantitative proteomics (SILAQ) is an innovative technology used in high throughput quantitative analysis of large protein complexes, protein-protein and protein-small molecule interactions. What the main functions of stable isotope labeling with amino acids?

Metabolomics is a study of a complete set of metabolites in a specific cell or organism. Targeted Metabolomics is a quantitative method for the identification and quantitative analysis of targeted metabolic compounds in organisms.Can targeted metabolomics technology help determine metabolities?

iTRAQ technology utilizes isobaric reagents to label the primary amines of peptides and proteins. The iTRAQ reagents usually consist of an N-methyl piperazine reporter group, a balance group, and an N-hydroxy succinimide ester group that is reactive with the primary amines of peptides. The balance groups present in each of the iTRAQ reagents function to make the labeled peptides from each sample isobaric and the quantification is facilitated through analysis of reporter groups that are generated upon fragmentation in the mass spectrometer. There are currently two mainly used reagents: 4-plex and 8-plex, which can be used to label all peptides from different samples/treatments. These samples are then pooled and usually fractionated by nano liquid chromatography and analyzed by tandem mass spectrometry (MS/MS).What is itraq labeling?

Does anyone know where can I get this kind of peptide sequence analysis service? Still N-terminal Edman sequencing has advantages for protein analysis that cannot readily be obtained by other analysis methods. Creative Proteomics provides N-terminal sequence analysis by both Edman and Mass spectrometry of therapeutic proteins, monoclonal antibodies and protein vaccines.

Fmoc and Boc methodologies are both employed, using solid and solution phase reactions. Boc-chemistry solid phase custom peptide synthesis allows us to synthesise difficult sequences, and gives a greater flexibility in the synthesis of modified peptides. Fmoc chemistry is most suitable for simple peptides and sequences prone to oxidation.How to customize a peptide synthesis service?

Peptide mass fingerprinting (PMF) is an analytical technique for protein identification. Basically, the unknown protein of interest is first cleaved into smaller peptides, whose absolute masses can be accurately measured with a mass spectrometer such as MALDI-TOF or ESI-TOF. Then these masses are compared to either a database containing known protein sequences or even the genome sequence which can be translated into proteins through computer programs. Then the absolute masses of the peptides from each protein are calculated theoretically for mass comparison between the peptides of the unknown protein and the theoretical peptide masses of each protein to find the best match. Is protein identification by peptide mass fingerprinting useful?

Nitric oxide (NO) is produced by three isoforms of nitric oxide synthase (NOS) and is a chemical messenger that reacts with free cysteine residues to form S-nitrothiols (SNOs). S-nitrosylation is a critical PTM used by cells to stabilize proteins, regulate gene expression and provide NO donors, and the generation, localization, activation and catabolism of SNOs are tightly regulated.Does protein s-nitrosylation analysis work well in protein Post-translational?

Due to their multiple involvement in biological systems, peptide biomarkers are ideal biomarker candidates. According to the NIH definition, "biomarker" has been defined as a characteristic that can be measured and evaluated as an indicator of normal biologic processes, pathologic processes or pharmacologic responses to therapeutic intervention. Since peptides can migrate between compartments of an organism, lots of pathogenic processes can be reflected by characteristic, pathognomonic changes of the composition of peptides in different body fluids. Peptide abundance changes associated with various diseases have already been detected.

Peptide mass fingerprinting pmf is an analytical technique for protein identification. Basically, the unknown protein of interest is first cleaved into smaller peptides, whose absolute masses can be accurately measured with a mass spectrometer such as MALDI-TOF or ESI-TOF. Then these masses are compared to either a database containing known protein sequences or even the genome sequence which can be translated into proteins through computer programs. Then the absolute masses of the peptides from each protein are calculated theoretically for mass comparison between the peptides of the unknown protein and the theoretical peptide masses of each protein to find the best match.

The advantage of PMF method is that only the masses of the peptides is need to be known, while time-consuming de novo peptide sequencing is then unnecessary, as long as the protein sequence is present in the database of interest. Additionally, most PMF algorithms assume that the peptides come from a single protein while the presence of a mixture can significantly complicate the analysis and potentially compromise the results, thus an isolated protein is needed for the PMF based protein identification. Mixtures exceeding a number of 2-3 proteins typically require the additional use of MS/MS based protein identification to achieve sufficient specificity of identification.

As for Protein Identification, there are many services and references.However, which one should be the best choice for your project? Can you offer some references related to protein identification methods use?