Transition state analog

For other types of analogs, see Analog (disambiguation).

Transition state analogs (transition state analogues), are chemical compounds with a chemical structure that resembles the transition state of a substrate molecule in an enzyme-catalyzed chemical reaction. Transition state analogs usually do not undergo a chemical reaction and can act as enzyme inhibitors by blocking their active site. Examples of drugs that are transition state analog inhibitors include flu medications such as the neuraminidase inhibitor oseltamivir and the HIV protease inhibitors saquinavir in the treatment of AIDS.

Mechanism

Like all catalysts, enzymes work by increasing the chemical reaction rate by stabilizing a high energy transition state intermediate which lowers the activation energy of the reaction. Transition state analogs that mimick this high-affinity intermediate but that do not undergo the catalyzed chemical reaction can therefore bind much stronger to an enzyme than simple substrate or product analogs.

See also

• Enzyme
• Structural analog, compounds with similar chemical structure
• Enzyme inhibitor
• Substrate analog
• Suicide inhibitor

References