Principles for Construction of Bioluminescent Enzyme Biotests for Analysis of Complex Media

ATP synthase FOF1 structure, function, and structure-based drug design

ATP synthases are unique rotatory molecular machines that supply biochemical reactions with adenosine triphosphate (ATP)-the universal "currency", which cells use for synthesis of vital molecules and sustaining life. ATP synthases of F-type (FOF1) are found embedded in bacterial cellular membrane, in thylakoid membranes of chloroplasts, and in mitochondrial inner membranes in eukaryotes. The main functions of ATP synthases are control of the ATP synthesis and transmembrane potential. Although the key subunits of the enzyme remain highly conserved, subunit composition and structural organization of ATP synthases and their assemblies are significantly different. In addition, there are hypotheses that the enzyme might be involved in the formation of the mitochondrial permeability transition pore and play a role in regulation of the cell death processes. Dysfunctions of this enzyme lead to numerous severe disorders with high fatality levels. In our review, we focus on FOF1-structure-based approach towards development of new therapies by using FOF1 structural features inherited by the representatives of this enzyme family from different taxonomy groups. We analyzed and systematized the most relevant information about the structural organization of FOF1 to discuss how this approach might help in the development of new therapies targeting ATP synthases and design tools for cellular bioenergetics control.

Design of bioluminescent biosensors for assessing contamination of complex matrices

The presence of potentially toxic xenobiotics in complex matrices has become rather the rule than the exception. Therefore, there is a need for highly sensitive inexpensive techniques for analyzing environmental and food matrices for toxicants. Enzymes are selectively sensitive to various toxic compounds, and, thus, they can be used as the basis for detection of contaminants in complex matrices. There are, however, a number of difficulties associated with the analysis of complex matrices using enzyme assays, including the necessity to take into account properties and effects of the natural components of the test media for accurate interpretation of results. The present study describes the six-stage procedure for designing new enzyme sensors intended for assessing the quality of complex matrices. This procedure should be followed both to achieve the highest possible sensitivity of the biosensor to potentially toxic substances and to minimize the effect of the uncontaminated components of complex mixtures on the activity of the biosensor. The proposed strategy has been tested in designing a bioluminescent biosensor for integrated rapid assessment of the safety of fruits and vegetables. The biosensor is based on the coupled enzyme system NAD(P)H:FMN-oxidoreductase and luciferase as the biorecognition element. The study describes methods and techniques for attaining the desired result in each stage. The proposed six-stage procedure for designing bioluminescent enzyme biosensors can be used to design the enzymatic biosensors based on other enzymes.