Hydrogen bonds play critical roles in protein structure, stability, and function. Most hydrogen bonds in proteins are derived from their crystal structures and the use of standard covalent geometry information, because the positions of hydrogen atoms are defined only in a limited number of ultrahigh-resolution crystal structures. On the other hand, NMR structure calculations rely mostly on the ...

The base-pairing interactions of promutagenic 06-methylguanine (06-MeGua) with cytosine and thymine in deuterated chloroform were investigated by 1H NMR spectroscopy. Nucleosides were derivatized at hydroxyl positions with triisopropylsilyl groups to obtain solubility in nonaqueous solvents and to prevent the ribose hydroxyls from forming hydrogen bonds. We were able to observe hydrogen-bonding...

Ecteinascidin 743 (ET743) is a marine natural product consisting of three linked tetrahydroisoquinoline subunits and an active carbinolamine functional group (Figure 1). ET743 displays potent antiproliferative activity against a variety of tumor cells and is currently undergoing phase II clinical trials.1 ET743 is known to bind to the minor groove of several DNA triplets containing a central gu...

The activity and denaturation extent of cellulase from Trichoderma reesei (E.C. # 3.2.1.4) was investigated in three representative N,N-dimethylethanolammonium akylcarboxylate ionic liquids. Significant cellulase activity and absence of enzyme unfolding was found in all concentrations of N,N-dimethylethanolammonium acetate (DMEAA), including the pure liquid. Activities in 20% and 40% (v/v) solu...

Hematopoietic prostaglandin (PG) D sythase (HPGDS) catalyzes the isomerization of PGH2, a common intermediate of various prostanoids, to PGD2, an inflammatory mediator, in the presence of glutathione (GSH). H-PGDS is activated by Mg, which increases the affinity of the enzyme for GSH and the turnover number. An evolutionary study revealed H-PGDS to be Correspondence/Reprint request: Dr. Yoshihi...