Chemically reactive immunogens lead to functional convergence of the immune response

H. Shulman, C. Makarov, A.K. Ogawa, F.E. Romesberg, E. Keinan, J. Am. Chem. Soc. (2000) 122:10743–10753.
pubpic2000shulmanHammett correlation studies of the aldol and retroaldol reactions catalyzed by antibodies 38C2 and 24H6 reveal that although the two antibodies have broad substrate specificities, they utilize slightly different mechanisms. Antibody 38C2 adopts a mechanism that is reminiscent of an acid-catalyzed aldol reaction, while antibody 24H6 follows a mechanism that is similar to the base-catalyzed reaction.


A Novel Copper-Mediated DNA Base Pair

E. Meggers, P.L. Holland, W.B. Tolman, F.E. Romesberg, P.G. Schultz, J. Am. Chem. Soc. (Comm.) (2000) 122:10714–10715.
pubpic2000meggersWe describe a base pair with a pyridine-2,6-dicarboxylate nucleobase (Dipic) as a planar tridentate ligand, and a pyridine nucleobase (Py) as the complementary single donor ligand. Characterization of this base pair in duplex DNA shows that interbase metal coordination can replace the hydrogen bonding schemes found in the natural base pairs dA:dT and dG:dC.


A phototautomerizable model DNA base pair

A.K. Ogawa, O.K. Abou-Zied, V. Tsui, R. Jimenez, D.A. Case, F.E. Romesberg, J. Am. Chem. Soc. (2000) 122:9917–9920.
pubpic2000ogawa2-(2‘-Hydroxyphenyl)benzoxazole (HBO) undergoes rapid photoinduced proton transfer from the enol-imine to the keto-amine tautomer. When incorporated in duplex DNA opposite an abasic site, HBO appears to be a good mimic of a natural DNA base pair based on duplex stability, UV and CD spectroscopy, and molecular dynamics simulations.


Stable and selective hybridization of oligonucleotides with unnatural hydrophobic bases

M. Berger, A.K. Ogawa, D.L. McMinn, Y. Wu, P.G. Schultz, F.E. Romesberg, Angew. Chem. Int. Ed. Engl. (2000) 39:2940-2942.
pubpic2000bergerRelying on only interbase hydrophobic packing for bonding, several unnatural nucleobases are reported that form selective and stable self-pairs in duplex DNA. These unnatural nucleobases should make it possible to increase the stringency and information content of hybridization or encoding experiments.


Efforts toward expansion of the genetic alphabet: information storage and replication with unnatural hydrophobic base pairs

A.K. Ogawa, Y. Wu, D.L. McMinn, J. Liu, P.G. Schultz, F.E. Romesberg, J. Am. Chem. Soc. (2000) 122(14):3274–3287.
pubpic2000cogawaWe show that the stability and selectivity of unnatural base pairs may be comparable to, or even exceed, that of native pairs and that the unnatural bases are orthogonal to the native bases, with correct pairing being favored by at least an order of magnitude relative to mispairing.