Photoreversibility and photostability in films of octopus rhodopsin isolated from octopus photoreceptor membranes

Abstract

In this work, a new biomaterial resulting from the isolation of octopus rhodopsin (OR) starting from octopus photoreceptor membranes is presented. Mass spectroscopic characterization was employed in order to verify the presence of rhodopsin in the extract. Photoreversibility and photochromic properties were investigated using spectrophotometric measurements and pulsed light. Thin films of OR were realized using the gel-matrix entrapment method in polyvinyl alcohol solution. The results indicate that the photoreversibility and the photostability of the OR in gel-matrices are maintained. Several measurements were performed to test the stability of the resulting biomaterial in time and at room temperature. Preliminary tests demonstrate that the photoreversibility and the photostability are still found after few days from the biomaterial preparation and after the exposure for several hours at room temperature.

A Novel Rhodopsin Gene from Octopus vulgaris for Optobioelectronics Materials

“…The unique photochromic retinal protein from rhabdomeric Octopus membranes -rhodopsin -has emerged as an outstanding material for biomolecular photonic applications due to its specific properties and advantages [7,8]. The unique properties of the OctR is that it is bistable and as a result -photoreversible.…”

“…OctR molecules maintain their functional activity at room temperature for several weeks [7]. OctR molecules have an ability to form thin films in gel-matrix [8].…”

“…All present attempts of heterologous expression of rho gene were based on E. dofleini sequence [11]. In previous studies we achieved photoreversibility and photostability in thin films of native rhodopsin from O. vulgaris [8]. Although vision rhodopsin of cephalopoda is conservative protein, some mismatches may slightly change its biophysical properties, probably, as result of adaptation to different habitat and sea water transparency.…”

“…Frozen octopus eyes were hemisected, and the retinas were collected and washed with buffer (4% NaCl, 50 mM Na-phosphate buffer pH 6.8), as described previously [8]. The isolated retinas were homogenized with the help of ExtractRNA kit (Evrogen, Russia).…”

Matrices for Sensors from Inorganic, Organic, and Biological Nanocomposites

“…Frozen eyes were hemisected, and the retinas were collected and washed with buffer A (4% NaCl, 50 mM Na-phosphate buffer pH 6.8). This procedure was carried out in dim red light [87,88,89,90]. The sample was loaded onto a sucrose cushion (40 mL 40% sucrose) and centrifuged for 60 min at 16,000 rpm in a Sorvall Centrifuge with rotor.…”