Activity of photosynthetic Reaction Centers coated with polydopamine
- PDF / 681,568 Bytes
- 10 Pages / 432 x 648 pts Page_size
- 72 Downloads / 182 Views
MRS Advances © 2020 Materials Research Society DOI: 10.1557/adv.2020.275
Activity of photosynthetic Reaction Centers coated with polydopamine Francesco Milano1, Marco Lopresti2, Danilo Vona,2 Gabrielle Buscemi2,3, Mariangela Cantore3, Gianluca M. Farinola2, Massimo Trotta3 1
Istituto di Scienze delle Produzioni alimentari CNR-ISPA, S. P. Lecce-Monteroni, I73100 Lecce 2Dipartimento di Chimica, Università degli Studi di Bari “Aldo Moro”, via Orabona 4, I-70126 Bari; 3Istituto per i Processi Chimico-Fisici CNR-IPCF, Dipartimento di Chimica, via Orabona 4, I-70126 Bari;
Dilute aqueous solutions of dopamine buff ered to an alkaline pH and in the presence of dissolved oxygen undergo to a series of autoxidation and rearrangement reactions that lead to the formation of a dark insoluble material called polydopamine (PDA) with melanin reminiscent properties. In this work we carried out this reaction in the presence of the photosynthetic reaction center (RC), a transmembrane pigment-protein complex responsible for the first light-induced reactions in the photosynthetic process. We have found that PDA grows in colloidal form around the RC and in the appropriate conditions the protein is entrapped in the PDA matrix without loss of functionality. The protein is still capable to perform its natural photocycle leading to the generation of photocurrents and the ubiquinone acceptor complex function is modulated by the PDA/RC ratio.
INTRODUCTION In recent years, the field of nanobiocatalysis with immobilized enzymes [1] or living microorganisms [2-3] has gained great attention thanks to the improved techniques to increase stability and activity of the biological catalysts. Several nanocarriers with porous structure and large surface/area ratio, such as SiO2 microparticles [4-5], have been proposed so far. These have been used in combination also in combination with carbon nanotube-derived mesopores[6], magnetic organosilica nanoflowers[7], protein-containing metal-organic frameworks-based hollow composites[8]. The enzyme activity is in many cases enhanced thanks to high loading and large particle surface/volume ratio.
1
Downloaded from https://www.cambridge.org/core. Cornell University Library, on 31 Aug 2020 at 02:50:42, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1557/adv.2020.275
In this framework, it is interesting to exploit the unique characteristic of polydopamine, a melanin-reminiscent dark and insoluble material formed by oxidative polymerization of alkaline solutions of its precursor dopamine [9]. The structure of polydopamine is heavily debated in literature [10-11] but some key points are widely accepted: the self-polymerization starts under weakly basic conditions via successive oxidation, followed by intramolecular cyclization, oligomerization and self-assembly, resulting in the highly cross-linked PDA final structure. The final solution results in a slow sedimenting colloidal suspension of PDA nanoaggregates stable for hour or days; moreover,
Data Loading...
