Interactions between aldehyde derivatives and the aldehyde binding site of bacterial luciferase

Abstract

The interaction of triazine aldehydes with the aldehyde binding site of bacterial luciferases was investigated using a series of triazine aldehydes with different aldehyde chain length, and substituents on the s-triazine ring. Substrate activity was determined using luciferase from Photobacterium fischeri and Vibrio harveyi in a dithionite-based luciferases assay. The chain length optimum was determined for two triazine aldehyde classes to be C-10 and C-11, respectively. Only the substrate activity of 10-(4-chloro-6-methylthio-s-triazine-2-yl)aminodecanal (5) was as high as n-decanal, the reference aldehyde. All other triazine derivatives reduced light emission, probably by hindered binding of the substrates. The degree of activity reduction correlated with the volume of the triazine ring moiety. The triazine moiety volume of compound 5 was estimated to be 200 x 10(-30) m3. Triazine aldehydes which showed reduced light emission had an estimated volume of 228 x 10(-30) m3 or greater. All triazine aldehydes showed approximately 10-fold lower activities for Vibrio harveyi than for Photobacterium fischeri luciferase. Substrate specificity was the same for both luciferases. A schematic superposition of quinone aldehydes and triazine aldehydes which showed substrate activities equivalent to n-decanal, indicated potential interaction sites of aldehyde substrates with the aldehyde binding site of bacterial luciferases. The in vivo relevance of the results is discussed.

Elemental sulfur: Toxicityin vivoandin vitroto bacterial luciferase,in vitroyeast alcohol dehydrogenase, and bovine liver catalase

“…The relativity of such classification of monooxygenases according their substrates (Lewis, 2001) could be confirmed by multiple data on monooxygenation by marine Vibrio (V. harveyi, V. fischeri) flavin-dependent monooxygenase of different groups of cytochrome P-450 substrates (like aldehydes, anesthetics, etc.) and their structural analogues (Curry et al, 1990, Danilov, Jegorov, 1990Jockers et al, 1995). Camphor was bound on a hydrophobic site of V. fischeri monooxygenase, the binding site of decanal, and caused immediate bioluminescence inhibition that could be restored after Ͼ 20 min because of its hydroxylation to hydrophilic 5-hydroxycamphor and its dissociation from monooxygenase (luciferase) both in vivo and in vitro (Danilov and Jegorov, 1990).…”

Inhibition of Electrochemically Controlled Bioluminescence of Bacterial Luciferase by n-Alkyl Alcohols

“…Therefore, FMNH2 should be regenerated from FMN to promote the luminescence reaction. For this purpose, a chemical reduction method with sodium dithionite (Na2S2O4) as the reducing agent has been commonly used; 26,27 however, it requires a large amount of reducing agent for the FMN reduction because of the rapid reoxidation of FMNH2 by dissolved oxygen. Moreover, the use of the reducing agent may affect the BL reaction steps, and then it cannot be used for the assay of drugs by the BL reaction.…”