116381-61-4Relevant articles and documents
cis-trans-Amide isomerism of the 3,4-dehydroproline residue, the 'unpuckered' proline
Kubyshkin, Vladimir,Budisa, Nediljko
, p. 589 - 593 (2016)
Proline (Pro) is an outstanding amino acid in various biochemical and physicochemical perspectives, especially when considering the cis-trans isomerism of the peptidyl-Pro amide bond. Elucidation of the roles of Pro in chemical or biological systems and engineering of its features can be addressed with various Pro analogues. Here we report an experimental work investigating the basic physicochemical properties of two Pro analogues which possess a 3,4-double bond: 3,4-dehydroproline and 4-trifluoromethyl-3,4-dehydroproline. Both indicate a flat pyrroline ring in their crystal structures, in agreement with previous theoretical calculations. In solution, the peptide mimics exhibit an almost unchanged equilibrium of the trans/cis ratios compared to that of Pro and 4-trifluoromethylproline derivatives. Finally we demonstrate that the 3,4-double bond in the investigated structures leads to an increase of the amide rotational barriers, presumably due to an interplay with the transition state.
Potent, small-molecule inhibitors of human mast cell tryptase. Antiasthmatic action of a dipeptide-based transition-state analogue containing a benzothiazole ketone
Costanzo, Michael J.,Yabut, Stephen C.,Almond Jr., Harold R.,Andrade-Gordon, Patricia,Corcoran, Thomas W.,De Garavilla, Lawrence,Kauffman, Jack A.,Abraham, William M.,Recacha, Rosario,Chattopadhyay, Debashish,Maryanoff, Bruce E.
, p. 3865 - 3876 (2007/10/03)
Inhibitors of human mast cell tryptase (EC 3.4.21.59) have therapeutic potential for treating allergic or inflammatory disorders. We have investigated transition-state mimetics possessing a heterocycle-activated ketone group and identified in particular benzothiazole ketone (2S)-6 (RWJ-56423) as a potent, reversible, low-molecular-weight tryptase inhibitor with a Ki value of 10 nM. A single-crystal X-ray analysis of the sulfate salt of (2S)-6 confirmed the stereochemistry. Analogues 12 and 15-17 are also potent tryptase inhibitors. Although RWJ-56423 potently inhibits trypsin (Ki = 8.1 nM), it is selective vs other serine proteases, such as kallikrein, plasmin, and thrombin. We obtained an X-ray structure of (2S)-6 complexed with bovine trypsin (1.9-? resolution), which depicts inter alia a hemiketal involving Ser-189, and hydrogen bonds with His-57 and Gln-192. Aerosol administration of 6 (2R,2S; RWJ-58643) to allergic sheep effectively antagonized antigen-induced asthmatic responses, with 70-75% blockade of the early response and complete ablation of the late response and airway hyperresponsiveness.
