Mass transfer induced interchange of the kinetic and thermodynamic control of enzymic peptide synthesis in biphasic water-organic systems

Enzymes to unravel bioproducts architecture

Enzymes are essential and ubiquitous biocatalysts involved in various metabolic pathways and used in many industrial processes. Here, we reframe enzymes not just as biocatalysts transforming bioproducts but also as sensitive probes for exploring the structure and composition of complex bioproducts, like meat tissue, dairy products and plant materials, in both food and non-food bioprocesses. This review details the global strategy and presents the most recent investigations to prepare and use enzymes as relevant probes, with a focus on glycoside-hydrolases involved in plant deconstruction and proteases and lipases involved in food digestion. First, to expand the enzyme repertoire to fit bioproduct complexity, novel enzymes are mined from biodiversity and can be artificially engineered. Enzymes are further characterized by exploring sequence/structure/dynamics/function relationships together with the environmental factors influencing enzyme interactions with their substrates. Then, the most advanced experimental and theoretical approaches developed for exploring bioproducts at various scales (from nanometer to millimeter) using active and inactive enzymes as probes are illustrated. Overall, combining multimodal and multiscale approaches brings a better understanding of native-form or transformed bioproduct architecture and composition, and paves the way to mainstream the use of enzymes as probes.

What makes a lipase a valuable acyltransferase in water abundant medium?

The necessity to develop more eco-friendly processes in oleochemistry has recently led to a renewed consideration of lipases exhibiting high acyltransferase activity in hydrated media.

Enzymatic catalysis via liquid-liquid interfaces

Enzymes acting in a biphasic liquid of water and organic solvent may show catalytic activity dependent on the amount of phase interface available. Such an effect may be caused by several mechanisms. For example, for hydroxynitrile lyase from Prunus amygdalus, substrate mass transfer limitation has been advocated, but also adsorption of the enzyme on the interface. In this commentary it is shown that often these two mechanisms will have qualitatively similar consequences. The reaction rate will be influenced by the organic substrate concentration, by the initial enzyme concentration, and by the volume-specific interfacial area, and these influences will be linear at low values but reach a saturation level at high values. To rule out any of the models, their quantitative mathematical descriptions should be compared, taking into account that both models may be valid simultaneously.