@article {2636,
	title = {Investigation of the Catalytic Mechanism of a Synthetic DNAzyme with Protein-like Functionality: An RNaseA Mimic?},
	journal = {Journal of the American Chemical Society},
	volume = {131},
	number = {15},
	year = {2009},
	note = {ISI Document Delivery No.: 434IJTimes Cited: 3Cited Reference Count: 108Thomas, Jason M. Yoon, Jung-Ki Perrin, David M.},
	month = {Apr},
	pages = {5648-5658},
	type = {Article},
	abstract = {The protein enzyme ribonuclease A (RNaseA) cleaves RNA with catalytic perfection, although with little sequence specificity, by a divalent metal ion (M2+)-independent mechanism in which a pair of imidazoles provides general acid and base catalysis, while a cationic amine provides electrostatic stabilization of the transition state. Synthetic imitation of this remarkable organo-catalyst ("RNaseA mimicry") has been a longstanding goal in biomimetic chemistry. The 9(25)-11 DNAzyme contains synthetically modified nucleotides presenting both imidazole and cationic amine side chains, and catalyzes RNA cleavage with turnover in the absence of M2+ similarly to RNaseA. Nevertheless, the catalytic roles, if any, of the "proteinlike" functional groups have not been defined, and hence the question remains whether 925-11 engages any of these functionalities to mimic aspects of the mechanism of RNaseA. To address this question, we report a mechanistic investigation Of 925-11 Catalysis wherein we have employed a variety of experiments, such as DNAzyme functional group deletion, mechanism-based affinity labeling, and bridging and nonbridging phosphorothioate substitution of the scissile phosphate. Several striking parallels exist between the results presented here for 925-11 and the results of analogous experiments applied previously to RNaseA. Specifically, our results implicate two particular imidazoles in general acid and base catalysis and suggest that a specific cationic amine stabilizes the transition state via diastereoselective interaction with the scissile phosphate. Overall, 925-11 appears to meet the minimal criteria of an RNaseA mimic; this demonstrates how added synthetic functionality can expand the mechanistic repertoire available to a synthetic DNA-based catalyst.},
	keywords = {ACID-BASE CATALYSIS, CLEAVING DNA ENZYME, COMPLEX, CYTOSOLIC FREE MAGNESIUM, DELTA VIRUS RIBOZYME, DINUCLEAR ZN(II), DIVALENT METAL-IONS, HAIRPIN RIBOZYME CATALYSIS, HDV GENOMIC, IN-VITRO SELECTION, RIBONUCLEASE-A, RIBOZYME},
	isbn = {0002-7863},
	url = {<Go to ISI>://000265268100049},
	author = {Thomas, J. M. and Yoon, J. K. and Perrin,David M.}
}
@article {430,
	title = {Toward an RNaseA mimic: a DNAzyme with imidazoles and cationic amines},
	journal = {Journal of the American Chemical Society},
	volume = {124},
	number = {34},
	year = {2002},
	note = {ISI Document Delivery No.: 586GJTimes Cited: 41Cited Reference Count: 52},
	month = {Aug},
	pages = {9960-9961},
	type = {Article},
	keywords = {CATALYTIC REPERTOIRE, CATIONS, CLEAVING DNA ENZYME, FUNCTIONALITIES, HAMMERHEAD, IN-VITRO SELECTION, MONOVALENT, NUCLEIC-ACIDS, RIBOZYME, SEQUENCE-SPECIFIC CLEAVAGE, SITE-SPECIFIC CLEAVAGE},
	isbn = {0002-7863},
	url = {<Go to ISI>://000177576000001},
	author = {Lermer, L. and Roupioz, Y. and Ting, R. and Perrin,David M.}
}
