Isotopically labeled compound refers to a compound with a special label obtained by replacing one or more atoms or chemical groups in a compound with an easily identifiable isotope or other easily identifiable nuclides or groups. This labeling process is also known as isotope labeling. Isotopically labeled compounds have a wide range of applications in scientific experiments and industrial production, such as biology, medicine, chemistry, materials science, environmental science, and other fields.
Commonly used isotope labeling compounds.
Among the many isotopes of carbon (c), 14C is the one most commonly used to label compounds. This isotope has a unique stability that allows weak radiation to be released during decay. Among a variety of amino acids, 14 C commonly used labeled compounds include leucine, lysine, proline, etc. Among them, the most commonly used labeled compound is leucine, as this amino acid is ubiquitous in a variety of proteins, making for a variety of options for 14C-labeled locations.
When 14C is used to label amino acids, it can be added to the -carbon atom of amino acids. This labeling method is very stable and can remain unchanged in cellular metabolism. Since leucine is widely found in proteins, it is one of the most commonly used amino acids. Leucine can be easily identified and replaced in polypeptide chains used for protein synthesis, making it easier for researchers to track and identify the protein synthesis process.
In addition to leucine, lysine and proline are commonly used labeling compounds. Lysine is an amino acid that contains two amino groups that reacts with the carbonyl group in the protein to form a stable link in the protein. Proline, on the other hand, is a subamino acid that is involved in the formation of peptide bonds during protein synthesis.
When applied to the bioactivity assay of mRNA, there are several options for the location of the 14C marker. This is because mRNA is a molecule that directs protein synthesis, and it can be linked to multiple amino acids. Therefore, 14C labeling can be performed both in the process of linking amino acids and in the process of peptide bond formation. As for the choice of amino acids for labeling, it depends on the properties and composition of the protein to be synthesized. In conclusion, 14 C labeled compounds have a wide range of applications in the fields of biochemistry and molecular biology, and can provide important tools and methods for studying protein synthesis and metabolism.
Commonly used markers for 3h are amino acids or nucleotides. The use of amino acids is the same as that of amino acids at 14 C. The most commonly used nucleosides in nucleotides, such as uracil and thymine, are used for nucleic acid labeling in bacterial and mammalian cell cultures. Among the nucleoside triphosphates, A-type NTP and DNTP are the most commonly used. Here n stands for four bases: A, G, C, U, or T. It is used for labeling of nucleic acids, such as nick translation markers. It can also be used for chromosome in situ hybridization or electron microscopy nucleic acid analysis.
The most commonly used amino acid labeled at 35 s is methionine, which is used for the same purpose as the 14 c label. [ 35 s] The oxygen in the position phosphate group in the DNTP is replaced with sulfur, and the nucleoside triphosphate obtained can be used for nucleotide sequence analysis and can also be used for nick translation to label DNA.
The commonly used markers of 32p are various nucleoside triphosphates. The 32 p markers fall into two broad categories. One is marked in the position and is used for phosphotransfer to label nucleic acids, and the other is marked in the position and used for nucleotide transfer labeling of nucleic acids. For example, [-32P]ATP is commonly used to label the ends of nucleic acids, while various [A-32P]dNTPs are used for nick translation labeling.
125 I is commonly used in sodium iodide solutions, which are mainly used to label single-stranded nucleic acids such as RNA and other molecules, as well as proteins.
Applications for Isotopically Labeled Compounds:
The 6th International Symposium on the Synthesis and Application of Isotope Disorder and Isotope Labeled Compounds was held in Philadelphia from September 14 to 18, 1997, with more than 400 participants from more than 20 countries and regions. More than 200 articles were published at the meeting, involving the application of more than 30 isotope disorders and labeling compounds. Among them, short-lived isotope disorders"c."C and F account for about 30 per cent. And long-lived isotopes"C, H and stable isotope D (deuterium) account for about 50%. Since the vast majority of compounds, especially organic compounds and biological brackets, contain carbon and hydrogen, the radioactive isotope of these two elements h,"c and"c et al. are used to label tracers to ensure that the structure of the labeled compound is exactly the same as that of the compound before labeling. Therefore, in the synthesis and application of labeled compounds, the isotope of hydrogen and carbon H,"c,"c isotopes are the most widely used.
The content of the conference includes the synthesis of labeled materials, the analysis and identification of labeled compounds, the application of isotopes and the treatment of radioactive waste. Isotope applications also include applications in clinical research and drugs, especially in pharmacology, pharmacokinetic studies, applications in organic and bioorganic synthesis, and applications in polymers (proteins. nucleic acids, monoclonal antibodies). Applications in drug metabolism and toxicology, as well as in pharmacology and agriculture.
The application of pharmacology mostly focuses on basic research in pharmacology and biochemical mechanism, such as systemic metabolism, bone calcium, anti-specific pharmacokinetics, the study of stable isotopes with biochemical drug tracers, the continuous flow of labeled compounds and the measurement of the proportion of isotopes, and the binding of radiopharmaceuticals in hemoglobin. In addition, there are some such as Alzheimer's disease, early diagnosis of hereditary chorea, arthropathy, etc., as well as early diagnosis and early diagnosis of breast cancer. Breast cancer is more common in women over the age of 40, and there are l80,000 new breast patients in the United States each year, of which 35% of patients died.
In order to reduce mortality, in addition to regular physical examination, early diagnosis is an important means to reduce mortality, and radiolabeled drugs are one of the important methods of early diagnosis, long-lived and short-lived radioisotope marker drugs are widely used in the evaluation of medicinal use in human bodies (healthy volunteers and patients) The method obtains a large number of sensitive and basic information that is impossible to obtain with other efficacy and pharmacokinetic behaviors and methods.
Rapid evaluation of total cell death, excretory balance, tissue distribution, and overall metabolism, among others, can all be obtained with labeled compounds of radioisotope disorders in the appropriate time. In recent years, great progress has been made in these aspects of research. Short-lived isotope disorders are also used to evaluate the mechanism of action of new drugs. PET (PositionemissionTomography) technology has been used to study physical and biochemical processes in vivo, measure biochemical and pharmacological processes in vivo, such as metabolic intermediates, early diagnosis of various cancers, and evaluate the internal response and effect of drug receptors. Agent-based metabolism. cerebral blood flow, neurotransmission and receptor transmission, etc. In particular, it is a diagnosis and treatment of diseases of the central nervous system.