A Multi-Scale Approach to Modeling the Interfacial Reaction Kinetics of Lipases with Emphasis on Enzyme Adsorption at Water-Oil Interfaces

Abstract

The enzymatic hydrolysis of triglycerides with lipases (EC 3.1.1.3.) involves substrates from both water and oil phases, with the enzyme molecules adsorbed at the water-oil (w/o) interface. The reaction rate depends on lipase concentration at the interface and the available interfacial area in the emulsion. In emulsions with large drops, the reaction rate is limited by the surface area. This effect must be taken into account while modelling the reaction. However, determination of the interfacial saturation is not a trivial matter, as enzyme molecules have the tendency to unfold on the interface, and form multi-layer, rendering many enzyme molecules unavailable for the reaction. A multi-scale approach is needed to determine the saturation concentration with specific interfacial area so that it can be extrapolated to droplet swarms. This work explicitly highlights the correlation between interfacial adsorption and reaction kinetics, by integration of the adsorption kinetics into the enzymatic reaction. The rate constants were fitted globally against data from both single droplet and drop swarm experiments. The amount of adsorbed enzymes on the interface was measured in a single drop with a certain surface area, and the enzyme interfacial loading was estimated by Langmuir adsorption isotherm.

Digital droplet RT‐LAMP increases speed of SARS‐CoV‐2 viral RNA detection

“…Previous studies have demonstrated that proteins can adsorb to oil–water interfaces due to the presence of both hydrophobic and hydrophilic domains 27–29 . We hypothesized that in our ddRT‐LAMP assay, the unexpected slowdown in assay time in smaller droplets resulted from surface adsorption at the oil‐water interface, and specifically from adsorption of the Bst 2.0 polymerase in the RT‐LAMP reaction.…”

“…Previous studies have demonstrated that proteins can adsorb to oil-water interfaces due to the presence of both hydrophobic and hydrophilic domains. [27][28][29] We hypothesized that in our ddRT-LAMP assay, the unexpected slowdown in assay time in smaller droplets resulted from surface adsorption at the oil-water interface, and specifically from adsorption of the Bst 2.0 polymerase in the RT-LAMP reaction. We hypothesized this protein adsorption at the oil-water interfaces in smaller droplets would lead to a reduction in the concentration of free Bst 2.0 available for the ddRT-LAMP reaction, resulting in longer assay times in smaller droplets.…”

High triacylglycerol turnover is required for efficient opening of stomata during heat stress in Arabidopsis

“…TAG levels and lipid droplet surface area are increased at 37°C in Col‐0 but not in pdat1 , such that the higher TAG hydrolysis rate in Col‐0 may initially simply reflect the larger lipid droplet surface area at 37°C without changing the lipase protein levels. The rate of TAG hydrolysis depends on the amount of active enzymes in the lipid‐water‐interphase and the surface area of the lipid droplet (Marangoni, 1994; Rusli et al., 2020). Alternatively, TAG degradation rates could be regulated in response to cellular demand for energy or C 2 carbon skeletons.…”

Immobilized CotA Laccase for Efficient Recovery of HEAVY OIL

“…In reality, MRGO-IDA-Cu-CotA laccase forms an additional layer at the interface of oil and solution, extending the interface by acting as an amphiphilic surfactant. As a result, the addition of MRGO-IDA-Cu-CotA laccase significantly lowers capillary forces while increasing capillary number [37]. Moreover, in the case of MRGO-IDA-Cu-CotA laccase (0.3 %wt), the interfacial tension values were reduced more than MRGO-IDA-Cu-CotA laccase (0.1 %wt) and MRGO-IDA-Cu-CotA laccase (0.2 %wt), as shown in Table 2.…”