@article {Daniel-Ivad2024-fb,
	title = {An imine reductase that captures reactive intermediates in the biosynthesis of the indolocarbazole reductasporine},
	journal = {J. Biol. Chem.},
	volume = {300},
	number = {2},
	year = {2024},
	pages = {105642},
	publisher = {Elsevier BV},
	abstract = {Imine reductases (IREDs) and reductive aminases have been used in the synthesis of chiral amine products for drug manufacturing; however, little is known about their biological contexts. Here we employ structural studies and site-directed mutagenesis to interrogate the mechanism of the IRED RedE from the biosynthetic pathway to the indolocarbazole natural product reductasporine. Cocrystal structures with the substrate-mimic arcyriaflavin A reveal an extended active site cleft capable of binding two indolocarbazole molecules. Site-directed mutagenesis of a conserved aspartate in the primary binding site reveals a new role for this residue in anchoring the substrate above the NADPH cofactor. Variants targeting the secondary binding site greatly reduce catalytic efficiency, while accumulating oxidized side-products. As indolocarbazole biosynthetic intermediates are susceptible to spontaneous oxidation, we propose the secondary site acts to protect against autooxidation, and the primary site drives catalysis through precise substrate orientation and desolvation effects. The structure of RedE with its extended active site can be the starting point as a new scaffold for engineering IREDs and reductive aminases to intercept large substrates relevant to industrial applications.},
	keywords = {biosynthesis, enzyme catalysis, enzyme structure, imine reductase, indolocarbazole, SITE-DIRECTED MUTAGENESIS, X-RAY CRYSTALLOGRAPHY},
	author = {Daniel-Ivad, Phillip and Ryan, Katherine S}
}
@article {2438,
	title = {A DNAzyme with Three Protein-Like Functional Groups: Enhancing Catalytic Efficiency of M2+-Independent RNA Cleavage},
	journal = {Chembiochem},
	volume = {10},
	number = {12},
	year = {2009},
	note = {ISI Document Delivery No.: 487MWTimes Cited: 5Cited Reference Count: 76Hollenstein, Marcel Hipolito, Christopher J. Lam, Curtis H. Perrin, David M.},
	month = {Aug},
	pages = {1988-1992},
	type = {Article},
	keywords = {BEACON SENSOR, biology, CLEAVING DNA ENZYME, CYTOSOLIC FREE MAGNESIUM, DEOXYRIBOZYMES, DNAzymes, enzyme catalysis, EVOLUTION, HAIRPIN RIBOZYME, HIGH-DENSITY, IN-VITRO SELECTION, ION, nucleic acids, NUCLEIC-ACIDS, RNAse A mimics, synthetic},
	isbn = {1439-4227},
	url = {<Go to ISI>://000269279700012},
	author = {Hollenstein, M. and Hipolito, C. J. and Lam, C. H. and Perrin,David M.}
}
@article {2104,
	title = {A highly selective DNAzyme sensor for mercuric ions},
	journal = {Angewandte Chemie-International Edition},
	volume = {47},
	number = {23},
	year = {2008},
	note = {ISI Document Delivery No.: 308BXTimes Cited: 46Cited Reference Count: 93Hollenstein, Marcel Hipolito, Christopher Lam, Curtis Dietrich, David Perrin, David M.},
	pages = {4346-4350},
	type = {Article},
	keywords = {AQUEOUS-MEDIA, BASE-PAIRS, CATALYTIC BEACON, DIVALENT, DNA, ENGINEERED ALLOSTERIC RIBOZYMES, enzyme catalysis, GOLD NANOPARTICLES, IN-VITRO SELECTION, mercury, MERR FAMILY PROTEINS, METAL-IONS, nucleic acids, NUCLEIC-ACID ENZYMES, SENSOR, sensors, TURN-ON},
	isbn = {1433-7851},
	url = {<Go to ISI>://000256364400014},
	author = {Hollenstein, M. and Hipolito, C. and Lam, C. and Dietrich, D. and Perrin,David M.}
}
@article {4978,
	title = {Reaction of human myoglobin and H2O2 - Involvement of a thiyl radical produced at cysteine 110},
	journal = {Journal of Biological Chemistry},
	volume = {275},
	number = {27},
	year = {2000},
	note = {ISI Document Delivery No.: 332QGTimes Cited: 55Cited Reference Count: 52},
	month = {Jul},
	pages = {20391-20398},
	type = {Article},
	abstract = {The human myoglobin (Mb) sequence is similar to other mammalian Mb sequences, except for a unique cysteine at position 110. Reaction of wild-type recombinant human Mb, the C110A variant of human Mb, or horse heart Mb with H2O2 (protein/H2O2 = 1:1.2 mol/mol) resulted in formation of tryptophan peroxyl (Trp-OO.) and tyrosine phenoxyl radicals as detected by EPR spectroscopy at 77 K. For wild-type human Mb, a second radical (g similar to 2.036) was detected after decay of Trp-OO. that was not observed for the C110A variant or horse heart Mb. When the spin trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO) was included in the reaction mixture at protein/DMPO ratios less than or equal to 1:10 mol/mol, a DMPO adduct exhibiting broad absorptions was detected. Hyperfine couplings of this radical indicated a DMPO-thiyl radical. Incubation of mild-type human Mb with thiol-blocking reagents prior to reaction with peroxide inhibited DMPO adduct formation, whereas at protein/DMPO ratios greater than or equal to 1:25 mol/mol, DMPO-tyrosyl radical adducts were detected. Mass spectrometry of wild-type human Mb following reaction with H2O2 demonstrated the formation of a homodimer (mass of 34,107 +/- 5 atomic mass units) sensitive to reducing conditions. The human Mb C110A variant afforded no dimer under identical conditions. Together, these data indicate that reaction of wild-type human Mb and H2O2 differs from the corresponding reaction of other myoglobin species by formation of thiyl radicals that lead to a homodimer through intermolecular disulfide bond formation.},
	keywords = {ASCORBATE, CROSS-LINKING, enzyme catalysis, HEMOGLOBIN, HYDROGEN-PEROXIDE, LOW-DENSITY-LIPOPROTEIN, METMYOGLOBIN, OXIDATION, SPERM WHALE MYOGLOBIN, SPIN ADDUCTS},
	isbn = {0021-9258},
	url = {<Go to ISI>://000088084500025},
	author = {Witting, P. K. and Douglas, D. J. and Mauk, A. G.}
}
@article {3923,
	title = {Uridine diphospho-alpha-D-gluco-hexodialdose: Synthesis and kinetic competence in the reaction catalyzed by UDP-glucose dehydrogenase},
	journal = {Angewandte Chemie-International Edition in English},
	volume = {36},
	number = {13-14},
	year = {1997},
	note = {ISI Document Delivery No.: XR042Times Cited: 9Cited Reference Count: 29},
	month = {Aug},
	pages = {1520-1522},
	type = {Article},
	keywords = {carbohydrates, enzyme catalysis, GROUP-A STREPTOCOCCI, intermediates, nucleotides, VIRULENCE},
	isbn = {0570-0833},
	url = {<Go to ISI>://A1997XR04200042},
	author = {Campbell, R. E. and Tanner, M. E.}
}
