Extreme halophilic archaea (haloarchaea) have adapted their physiology and biomolecules to thrive in saline
environments (>2 M NaCl). Many haloarchaea produce extracellular hydrolases (including proteases) with
potential biotechnological applications, which require unusual high salt concentrations to attain their
function and maintain their stability. These conditions restrict many of the standard methods used to
study these enzymes such as activity determination and/or protein purification. Here, we describe basic
protocols to detect and measure extracellular proteolytic activity in haloarchaea including casein hydrolysis
on agar plates, quantitative proteolytic activity determination by the azocasein assay and gelatin zymography
in presence of the compatible solute glycine-betaine.
Paggi, R.A., Giménez, M.I., De Castro, R.E. (2022). Proteolytic Activity Assays in Haloarchaea. In: Ferreira-Cerca, S. (eds) Archaea. Methods in Molecular Biology, vol 2522. Humana, New York, NY. https://doi.org/10.1007/978-1-0716-2445-6_20
Link to chapter: https://link.springer.com/protocol/10.1007/978-1-0716-2445-6_20