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A ribonucleic acid (RNA) molecule that, like a protein, can catalyze specific biochemical reactions. Examples include self-splicing rRNA and RNase P, both involved in catalyzing RNA processing reactions (that is, the biochemical reactions that convert a newly synthesized RNA molecule to its mature form). Different ribozyme structures catalyze quite distinct RNA processing reactions, just as protein enzyme families that are composed of different structures catalyze different types of biochemical reactions.

Ribozymes share many similarities with protein enzymes, as assessed by two parameters that are used to describe a biological catalyst. The Michaelis-Menten constant Km relates to the affinity that the catalyst has for its substrate, and ribozymes possess Km values which are comparable to Km values of protein enzymes. The catalytic rate constant describes how efficiently a catalyst converts substrate into product. The values of this constant for ribozymes are markedly lower than those values observed for protein enzymes. Nevertheless, ribozymes accelerate the rate of chemical reaction with specific substrates by 1011 compared with the rate observed for the corresponding uncatalyzed, spontaneous reaction. Therefore, ribozymes and protein enzymes are capable of lowering to similar extents the activation energy for chemical reaction. See Enzyme, Protein, Ribonucleic acid (RNA)


A ribonucleic acid molecule that can catalyze, or lower the activation energy for, specific biochemical reactions.
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The new enzyme is called a ribozyme because it is made from ribonucleic acid (RNA).
It is collectively autocatalytic in that virtually all steps are protein catalyzed reactions, save the ribozyme itself.
Previous research by Liu and Lu showed that Salmonella could effectively sneak the anti-viral ribozymes into human cells infected with human cytomegalovirus and reduce the viral load of the cell cultures.
The team looked at a lab-grown ribozyme that catalyzes the Diels-Alder reaction, which has broad applications in organic chemistry.
The team got strands that were 32 building blocks long, while the full-length ribozyme is 190.
The Vif5113 and Vif5113A ribozymes were synthesized (5'ACA TAT GGT GTT TCT GAT GAG TCC GTG AGG ACG A/GAA CTA ATC TTT TCC AT 3') and cloned into the shuttle vector pPCR-Script (Stratagene) as previously described (18).
In fact, when subject to evolution some of the descendants of the ribozymes created by Bartel and Johnson ended up 100 times more efficient than their ancestors.
Kinetic characterization of ribozymes can give valuable information about reaction mechanisms and a standard for the "fitness" of a ribozyme.
RPI relocated from Cleveland to Colorado in 1992 to be closer to CU-Boulder's Nobel Prize-winning Professor Tom Cech, whose discovery of ribozymes the company has sought to commercialize.
If functional nucleic acids or ribozymes are present in nature, or are relatively easy to generate by in vitro selection - the argument goes - then similar functional nucleic acids or ribozymes could have also existed during the evolution of an RNA world.
Naturally occurring ribozymes may be used in chemotherapy, but they are large, expensive, and fragile RNA molecules.
The idea: Into certain strategic cells, insert molecular strands called ribozymes that destroy HIV.