Part II: Everything You Need to Know About Metabolomics Research

Part I: Everything You Need to Know About Metabolomics Research

Matrix-assisted laser desorption/ionization (MALDI) is a mild ionization method that can obtain intact mass spectrometry information of some macromoleculars which are easily dissociated into fragments by conventional ionization methods, such as DNA, proteins, peptides and sugars. Matrix-assisted laser desorption/ionization (MALDI) is a mild ionization method that can obtain intact mass spectrometry information of some macromoleculars which are easily dissociated into fragments by conventional ionization methods, such as DNA, proteins, peptides and sugars. Desorption electrospray ionization (DESI) is a direct ionization technique that allows direct analysis of samples under atmospheric conditions with tandem mass spectrometry. The principle is to use a fast moving charged solution stream to extract samples of the contact surface, which can be used for forensic analysis, analysis of drugs, plants, biological tissues, polymers, etc. Laser ablation electrospray Ionization (LAESI) is a direct ionization technique that combines mid-infrared laser ablation and secondary electrospray ionization for a wide range of samples, including plants, tissues, cells, and even untreated biological solutions such as blood, urine, and so on. It has been used in the fields like food and drug regulation.

metabolomics analysis
 Nuclear magnetic resonance spectrum does not need to separate the metabolic components in advance. Compared with mass spectrometry, it has the advantages of good reproducibility, simple sample preparation, no prior separation, and low destructiveness to the sample. Although its sensitivity phase is lower (It is controversial. Some scholars believe that this is caused by incorrect sample pretreatment workflow), its ease-to-use feature makes it a widely used method.

Apart from the above ones, there are other detection methods, which include ion-mobility spectrometry (IMS), electrochemical detection techniques coupled with high-performance liquid chromatography (HPLC-ECD) and Raman spectroscopy. IMS is a technique for separating and analyzing these molecules based on the migration of ionized molecules in a gas phase carrier. It has high sensitivity and can be used alone or in series with mass spectrometry, gas chromatography or liquid chromatography. HPLC-ECD can be used to measure low-level components in complex matrices. It has the features of ease-to-use, sensitivity and selectivity, and has been used in clinical research, food testing, drug testing and other fields. Raman spectroscopy is based on vibrational spectroscopy and is capable of detecting compound structures and small changes. It has the advantages of not destroying samples, easy sample preparation, and high spatial resolution. It is applied to clinical pathology research, microbial classification and detection, compound analysis and other fields.

Metabolomics Related Databases and Commonly Used Software

metabolomics
Commonly used metabolomics related databases include the Human Metabolome Database (HMDB), the Small Molecule Pathway Database (SMPDB), the Kyoto Encyclopedia of Genes and Genomes (KEGG), and the Reactome database, the MassBank database, the BioCyc database, the METLIN database, the FiehnLib database, the NIST/EPA/NIH Mass Spectral Library database, the MetaCyc database, the MMCD database, etc. 

Comments

Post a Comment

Popular posts from this blog

Practice of N-terminal Sequencing by Edman Degradation Technology in Protein and Peptide Sequence Analysis

Image
The N-terminal amino acid sequence of protein is one of the key quality attributes of biological drugs. N-terminal sequencing by Edman degradation  is a routine method to analyze this property. The analysis of 15 amino acid sequences on the N-terminal by Edman degradation method is usually a necessary item when applying for biological drugs . At  the same time, it is also an annual inspection item of many listed biological drugs (see Pharmacopoeia 2015). In scientific research, N-terminal sequencing can be used to provide key information for the confirmation of unknown or uncertain theoretical sequences. So this method is widely used in scientific research and industry.  W hat are its principles ? H ow to analyze the results ? Advice for sample delivery? P rinciples In short, we can understand it from these two aspects: The first step  is Edman degradation . T hrough the reaction of PITC (Phenylisothiocyanate), an organic reagent, and α - amino acid at the N-terminal of pr
Read more

Part I: Basic Knowledge of Quantitative Analysis of Protein Acetylation Modification

Image
After the protein is translated in the cell, it is processed through a very important step before being transported to the corresponding organelle and undergoing specific biological effects. The role of protein   post-translational modification   ( PTM ) is primarily to alter the activity, localization or function of the protein. Protein PTM  also further increases the diversity and complexity of cellular pathway mechanisms and life activities. Except for acetylation , c ommon protein PTM  include s   phosphorylation , glycosylation , ubiquitination , and the like. Protein  A cetylation  M odification Protein acetylation modification, as the name suggests, refers to the grafting of acetylated groups on the original basis of the protein. In cells, the acetylation modification reaction is catalyzed by an acetyltransferase, and the acetyl group of acetyl-CoA is transferred and added to the protein lysine residue. In earlier studies, acetylation has been considered to be a pos
Read more

De Novo Protein Sequencing Procedures and Features

Image
The sequence of a protein molecule is the basis for the function of a protein. Accurate determinat ion of protein sequence plays an important role in the study of protein functional epitopes, detection of commercial monoclonal antibodies, vaccines, and kits. Although there are many studies on protein sequencing, accurate sequencing of proteins is still not as fast and accurate as that of DNA. Protein sequencing is mainly hampered by the purification of protein samples, and the complexity of factors that make up the amino acid com position of proteins. De novo   protein sequencing  is  also called novel protein sequencing. This technique deduces t he amino acid sequence based on the difference in mass between a series of regular fragment ions generated by the peptide collision with an inert gas. We can guess the amino acid sequence and post-translational modifications based on the y ion and b ion at the cleavage of the peptide bond. De novo  sequencing has a unique advantage that t
Read more