Abstract
Enzymes isolated from organisms found in cold habitats generally exhibit higher catalytic activity at low temperatures than their mesophilic homologs and are therefore known as cold-active enzymes. Cold-active proteases are very useful in a variety of biotechnological applications, particularly as active ingredients in laundry and dishwashing detergents, where they provide strong protein-degrading activity in cold water. We identified a cold-active protease (Pro21717) from a psychrophilic bacterium, Pseudoalteromonas arctica PAMC 21717, and determined the crystal structure of its catalytic domain (CD) at a resolution of 1.4 Å. The Pro21717-CD structure shows a conserved subtilisin-like fold with a typical catalytic triad (Asp185, His244, and Ser425) and contains four calcium ions and three disulfide bonds. Interestingly, we observed an unexpected electron density at the substrate-binding site from a co-purified peptide. Although the sequence of this peptide is unknown, analysis of the peptide-complexed structure nonetheless provides some indication of the substrate recognition and binding mode of Pro21717. Moreover, various parameters, including a wide substrate pocket size, an abundant active-site loop content, and a flexible structure provide potential explanations for the cold-adapted properties of Pro21717. In conclusion, this is first structural characterization of a cold-adapted subtilisin-like protease, and these findings provide a structural and functional basis for industrial applications of Pro21717 as a cold-active laundry or dishwashing detergent enzyme.
Highlights
In recent years, the interest in cold-active enzymes as potential candidates for biotechnological applications has grown [1]
Psychrophilic proteases in particular have the potential for commercial use, especially as laundry detergent enzymes owing to their higher activities during washing processes that take place in cold tap water
A genomic library from Polar and Alpine Microbial Collection (PAMC) 21717, consisting of approximately 1.2 × 105 fosmid clones, was screened for clear halo production around colonies on LB plates supplemented with skim milk
Summary
The interest in cold-active (psychrophilic) enzymes as potential candidates for biotechnological applications has grown [1]. Psychrophilic enzymes from cold-adapted microorganisms have higher catalytic efficiencies than their mesophilic counterparts [2]. Psychrophilic proteases in particular have the potential for commercial use, especially as laundry detergent enzymes owing to their higher activities during washing processes that take place in cold tap water (below 15 ̊C). Psychrophilic alkaline proteases have attracted much interest from industrial enzyme manufacturers for inclusion in new laundry detergent formulations because of their higher cold-activity and stability under harsh washing conditions. The activities of only a few psychrophilic proteases have been characterized at low temperatures [5,6,7,8]. Contrary to our expectations, limited studies have been performed to characterize the performance of psychrophilic proteases as additives in laundry and dishwashing detergents
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
