An X-ray diffraction study on a single rod outer segment from frog retina

Abstract

X-ray diffraction patterns were recorded from isolated single rod outer segments of frog. The outer segments in Ringer's solution were exposed to a 6 mm microbeam (15 keV) at the BL40XU beamline, SPring-8. The diffraction pattern demonstrated a remarkable regularity in the stacking and flatness of the disk membranes. The electron density profile calculated from the intensity of up to tenth-order reflections showed a pair of bilayers that comprise a disk membrane. The structure of the disk membrane and the changes in the profile on swelling generally agreed with previous reports. Radiation damage was significant with an irradiation of 5 Â 10 5 Gy which is much lower than the known damaging dose on proteins at the liquid-nitrogen temperature.

3D nanoscope analyses on the retinas of mouse (Mus musculus)

“…This lamellar stacking, with a periodicity of 30.0 nm (300 Å), originates in a linear arrangement of disk membranes in the outer segment of retinal rod. The similar observations have been also recorded in the previous published studies for isolated mouse eyeballs (30.4 nm) and the frog eye retinal rod (29.3 nm) [19]. The other determined and measured structural parameters can also be given as, the total length of seven membrane alpha helices = 252 Å, the thickness of membrane disc= 208 Å, the mean rhodopsin size = 148 Å, the distance of intermembranes 40 Å and the thickness of membrane bilayer = 36 Å.…”

Nanoscale structural analyses on Rod Outer Segments (ROS) membranes and retina of bovine eye: 3D structure of photoreceptor nanodomains

“…This lamellar stacking, with a periodicity of 30.0 nm (300 Å), originates in a linear arrangement of disk membranes in the outer segment of retinal rod. The similar observations have been also recorded in the previous published studies for isolated mouse eyeballs (30.4 nm) and the frog eye retinal rod (29.3 nm) [36].…”