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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)

McGraw-Hill Concise Encyclopedia of Bioscience. © 2002 by The McGraw-Hill Companies, Inc.


A ribonucleic acid molecule that can catalyze, or lower the activation energy for, specific biochemical reactions.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
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Instead, he glosses over the problem of explaining the origin of proteins (or ribozymes with specific protein-like functions).
However, there are issues that have held up the clinical development of ribozymes and antisense molecules are target selection, specificity and delivery along with low efficiency, short-period of maintenance, and high cost (82).
I tried to point out where it runs into base pairing between the template and the ribozyme, so the same interactions that it uses to bind the template inhibit further polymerization.
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First, we have isolated ribozymes that can catalyze the formation of CoA, NAD and FAD from their respective precursors (phosphopantetheine, NMN, and FMN), suggesting a plausible mechanism of coenzyme synthesis and utilization in the RNA world.
In vitro evolution of a self-alkylating ribozyme. Nature 1995;374:777-82.
After that, they used a harmless virus to load the stem cells with an extra gene that makes a ribozyme - a pair of molecular "scissors" targeted at the virus.
Rigel has several issued patents covering screening for antiviral agents where IRES (internal ribozyme entry site) is the drug target.