High stabilization of immobilized Rhizomucor miehei lipase by additional coating with hydrophilic crosslinked polymers: Poly-allylamine/Aldehyde–dextran. (May 2020)

• Record Type: Journal Article
• Authors: Cejudo-Sanches, Janaina; Orrego, Alejandro H.; Jaime-Mendoza, Adriana; Ghobadi, Rohollah; Moreno-Perez, Sonia; Fernandez-Lorente, Gloria; Rocha-Martin, Javier; Guisan, José M.
• Is Part Of: Process biochemistry. Volume 92(2020)
• Page Start: 156
• Page End: 163
• Publication Date: 2020-05
• Subjects: Lipases -- Immobilization -- Thermal stabilization -- Cross-linked polymers -- Polyallylamine -- Aldehyde-dextran; Biochemical engineering -- Periodicals; Biotechnology -- Periodicals; Biochemistry -- periodicals; Biotechnology -- periodicals; Chemical Engineering -- periodicals; Génie biochimique -- Périodiques; Biotechnologie -- Périodiques; Biochemical engineering; Biotechnology; Periodicals; 660.63
• DOI: 10.1016/j.procbio.2020.02.026
• Languages: English
• ISSNs: 1359-5113

Abstract

Graphical abstract: Highlights: R. miehei lipase was adsorbed on octyl agarose and coated with poly-allylamine (PAA). PAA-coated lipase derivative was 4-fold more stable than uncoated derivative. Lipase derivative was coated with PAA and crosslinked with aldehyde-dextran. PAA-coated lipase and crosslinked with aldehyde-dextran promoted highly stability. Improved derivatives preserved 6-fold more enzyme activity than the soluble lipase. Abstract: Immobilized enzymes have a very large surface region which is not in contact with the support surface and, thus, have potential as a target for novel stabilization strategies. In this paper, coating the surfaces of such enzymes with a highly hydrophilic and compact cross-linked poly-aminated polymer as a strategy to increase the thermal stability of the immobilized enzymes is proposed. In particular, Rhizomucor miehei lipase (RML) was immobilized by interfacial adsorption onto octyl-agarose and further coated with poly-allylamine (PAA), a polymer that is very rich in primary amino groups. Cross-linking of the PAA layer to coat the immobilized enzyme was carried out, in situ, by reaction with freshly oxidized dextran (aldehyde–dextran). The PAA layer only exerted moderate stabilizing effects (around 4-fold), but further cross-linking with aldehyde–dextran highly increased the stabilizing effects; the new derivative was 440-fold more stable than uncoated derivative at 55 °C and pH 7 and exhibited 6-fold more catalytic activity compared to the soluble enzyme used for immobilization. We hypothesize that the hydrophilicity of PAA reduces the exposure of internal hydrophobic pockets to the enzyme surface at high temperatures. Besides, the compactness of the polymer may reduce distortion of the enzyme surface during inactivation.