Specifc chemical incorporation of l‑DOPA and functionalized l‑DOPA‑hyaluronic acid in Candida antarctica lipase: creating potential mussel‑inspired bioadhesives

Abstract

12 pags., 8 figs., 4 tabs. ; Mussel adhesives proteins have been extensively studied as a promising alternative in bioadhesives due to their ability to provide durable anchoring under diferent surfaces in seawater. These charasteristics have been attributed to the presence of the reduced catechol form, 3,4-dihydroxyphenylalanine (DOPA) of its structure. However, its practical applications have been limited due to drawbacks with natural extraction. Here, a novel method have been described for site-specifc chemical incorporation of l-3,4-dihydroxyphenylalanine methyl ester (l-DOPAME) into proteins, in particular Candida antartica fraction B (CAL-B) lipase. Two strategies were followed, direct conjugation of DOPA at the C-terminus on the surface of the protein, and protein conjugation with tailor-made glycopolymers (DOPA-hyaluronic acid (HA) polymers) at the N-terminus. In all cases, the characterization of the new DOPA-proteins was carried out using circular dichroism, fuorescence or mass spectrometry. ; An improvement in the activity (in some cases more than 2 times) or the thermostability of CAL-B (with a half live 4 fold greater in some cases) was found by the incorporation of DOPA molecules. These DOPA-proteins showed excellent underwater covalent adhesive ability on amino functionalized surfaces in aqueous media compared to other modifed [e.g. tyrosine modifed (TYR)] CAL-B proteins. At pH 8.5, CALB-DOPA proteins were completely adsorbed after 90 min of incubation, whereas about 10% of CALB-HA or CALB-TYR proteins were adsorbed at the same time. Native CAL-B adsorption was not observed. These results suggest a potential application of these DOPA-proteins as bioglues or bioadhesives for practical underwater applications. ; s This work was supported by the Spanish National Research Council (CSIC), Fondo de Investigaciones Sanitarias from Instituto de Salud Carlos III, and European Union (ERDF/ ESF, 'Investing in your future') (PI15/00663 and PI18/00349 to OA); Diputación General de Aragón (Translation Research group in Digestive Pathology Group—E25_17R to OA); and Centro de Investigación Biomédica en Red en Enfermedades Hepáticas y Digestivas (CIBERehd). The authors thank the COST Action CA15216 (ENBA) for COST meeting support. We also thank Dr. Martinez from Novozymes and Proteomics Facility of Servicios Científco Técnicos del CIBA (IACS-Universidad de Zaragoza), ProteoRed ISCIII, Zaragoza, Spain. ; Peer reviewed