CRM197
CRM197[edit | edit source]
CRM197 is a non-toxic mutant of diphtheria toxin that is used in various medical and research applications, particularly as a carrier protein in conjugate vaccines. It is a genetically modified form of the diphtheria toxin, where a single amino acid substitution (glycine to glutamic acid at position 52) renders it non-toxic.
Structure and Function[edit | edit source]
CRM197 is structurally similar to the native diphtheria toxin, but the mutation in its active site prevents it from inhibiting protein synthesis in cells, which is the mechanism by which the diphtheria toxin exerts its toxic effects. Despite this, CRM197 retains the ability to bind to the heparin-binding epidermal growth factor-like growth factor (HB-EGF) receptor, which is the same receptor used by the diphtheria toxin to enter cells.
Applications[edit | edit source]
CRM197 is widely used as a carrier protein in conjugate vaccines. Conjugate vaccines are designed to improve the immunogenicity of polysaccharide antigens, which are typically poorly immunogenic on their own. By conjugating these polysaccharides to a protein carrier like CRM197, the immune system is better able to recognize and respond to the antigen.
Some of the vaccines that utilize CRM197 as a carrier protein include:
- Pneumococcal conjugate vaccine
- Haemophilus influenzae type b (Hib) vaccine
- Meningococcal conjugate vaccine
Research and Development[edit | edit source]
CRM197 is also used in research settings to study receptor-mediated endocytosis and to investigate the mechanisms of toxin entry into cells. Its ability to bind to the HB-EGF receptor without causing toxicity makes it a valuable tool for studying cellular processes.
Safety and Efficacy[edit | edit source]
CRM197 is considered safe for use in humans, as it lacks the toxic activity of the native diphtheria toxin. Its use in vaccines has been associated with a strong immune response and has contributed to the effectiveness of several important vaccines.
History[edit | edit source]
The development of CRM197 as a non-toxic variant of diphtheria toxin was a significant advancement in vaccine technology. It was first described in the 1970s and has since become a standard component in many conjugate vaccines.
Also see[edit | edit source]
Search WikiMD
Ad.Tired of being Overweight? Try W8MD's physician weight loss program.
Semaglutide (Ozempic / Wegovy and Tirzepatide (Mounjaro / Zepbound) available.
Advertise on WikiMD
|
WikiMD's Wellness Encyclopedia |
| Let Food Be Thy Medicine Medicine Thy Food - Hippocrates |
Translate this page: - East Asian
中文,
日本,
한국어,
South Asian
हिन्दी,
தமிழ்,
తెలుగు,
Urdu,
ಕನ್ನಡ,
Southeast Asian
Indonesian,
Vietnamese,
Thai,
မြန်မာဘာသာ,
বাংলা
European
español,
Deutsch,
français,
Greek,
português do Brasil,
polski,
română,
русский,
Nederlands,
norsk,
svenska,
suomi,
Italian
Middle Eastern & African
عربى,
Turkish,
Persian,
Hebrew,
Afrikaans,
isiZulu,
Kiswahili,
Other
Bulgarian,
Hungarian,
Czech,
Swedish,
മലയാളം,
मराठी,
ਪੰਜਾਬੀ,
ગુજરાતી,
Portuguese,
Ukrainian
Medical Disclaimer: WikiMD is not a substitute for professional medical advice. The information on WikiMD is provided as an information resource only, may be incorrect, outdated or misleading, and is not to be used or relied on for any diagnostic or treatment purposes. Please consult your health care provider before making any healthcare decisions or for guidance about a specific medical condition. WikiMD expressly disclaims responsibility, and shall have no liability, for any damages, loss, injury, or liability whatsoever suffered as a result of your reliance on the information contained in this site. By visiting this site you agree to the foregoing terms and conditions, which may from time to time be changed or supplemented by WikiMD. If you do not agree to the foregoing terms and conditions, you should not enter or use this site. See full disclaimer.
Credits:Most images are courtesy of Wikimedia commons, and templates, categories Wikipedia, licensed under CC BY SA or similar.
Contributors: Prab R. Tumpati, MD
