The question of whether lipases can be activated by adsorption onto an interface in organic solvents was addressed using Rhizomucor miehei lipase as a model. In aqueous solution, this enzyme was shown t o undergo a marked interfacial activation. However, lipase (either Iyophilized or precipitated from water with acetone) suspended in ethanol or 2-(2-ethoxyethoxy)ethanol containing triolein exhibited no jump in catalytic activity when the concentration of triolein exceeded its solubility in these solvents, thereby resulting in formation of an interface. To test whether the lack of interfacial activation was due to the insolubility of the enzyme in organic media, lipase was covalently modified with poly(ethy1ene glycol). The modified lipase, although soluble in nonaqueous media, was still unable t o undergo interfacial activation, regardless of the hydrophobicity of the interface. This inability was found t o becaused by the absence of adsorption of lipase onto interfaces in organic solvents, presumably because of the absence of the hydrophobic effect (the driving force of lipase adsorption onto hydrophobic interfaces in water) in such media. The uncovered lack of interfacial adsorption and activation suggests that the short a-helical "lid" covering the active center of the lipase remains predominantly closed in nonaqueous media, thus contributing t o diminished enzymatic activity.

No abstract

Metallothioneins (MTs) are small molecular weight stress response proteins that play a central role as reservoir of essential divalent heavy metal cations such as zinc and copper, and also can diminish the effects of toxic heavy metals such as mercury and cadmium. Historically, MT has been considered to be an intracellular protein with roles to play in the management of heavy metals, as a regulator of cellular redox potential, and as a buffer of free radicals. Our recent studies have highlighted immunomodulatory role of MT in inflammatory diseases and also in the progression of metastatic cell movement. Hence, manipulation and detection of MT is essential for its possible use as a diagnostic and in therapeutic interventions of chronic inflammation. This review describes procedures used to detect MT using techniques such as western immunoblot, competition ELISA, flow cytometry and immunohistochemistry. Additionally, it also describes the use of a colorimetric cell proliferation assay (CellTiter 96 AQ One Solution/MTS) to study the proliferative effect of MT. © 2017 by John Wiley & Sons, Inc.

This review is aimed at generating a wide‐scale perspective of the current ways in which an extensive range of industrial products are produced, and how the move towards carbohydrate‐based industries has not only started, but is well under way. It is separated into two fundamental parts. In the first the role of biofuel production is examined, and in the second the role of speciality chemicals and enzymes is outlined, the latter not just as biocatalysts, but also as end products.

The question of whether lipases can be activated by adsorption onto an interface in organic solvents was addressed using Rhizomucor miehei lipase as a model. In aqueous solution, this enzyme was shown to undergo a marked interfacial activation. However, lipase (either lyophilized or precipitated from water with acetone) suspended in ethanol or 2‐(2‐ethoxyethoxy)ethanol containing triolein exhibited no jump in catalytic activity when the concentration of triolein exceeded its solubility in these solvents, thereby resulting in formation of an interface. To test whether the lack of interfacial activation was due to the insolubility of the enzyme in organic media, lipase was covalently modified with poly(ethylene glycol). The modified lipase, although soluble in nonaqueous media, was still unable to undergo interfacial activation, regardless of the hydrophobicity of the interface. This inability was found to be caused by the absence of adsorption of lipase onto interfaces in organic solvents, presumably because of the absence of the hydrophobic effect (the driving force of lipase adsorption onto hydrophobic interfaces in water) in such media. The uncovered lack of interfacial adsorption and activation suggests that the short α‐helical “lid” covering the active center of the lipase remains predominantly closed in nonaqueous media, thus contributing to diminished enzymatic activity. © 1996 John Wiley & Sons, Inc.