Nanostructural ordering of epithelial tissue of silk gland of Antheraea mylitta silkworm
- Dr. Alvina VAZINA
- Dr. Alvina VAZINA (Institute of theoretical and experimental biophysics, RAS)
- Anna VASILIEVA (Institute of Theoretical and Experimental Biophysics, RAS, Pushchino, Russia)
- Nadezhda LANINA (Institute of Theoretical and Experimental Biophysics, RAS, Pushchino, Russia)
- Aleksander ZABELIN (National Research Center “Kurchatov Institute”, Moscow, Russia)
- Dr. Vladivir KORNEEV (Institute of Cell Biophysics, RAS, Institutskaya ul. 3, 142290, Pushchino, Russia)
- Vera STEPANOVA (National Research Center “Kurchatov Institute”, Moscow, Russia)
- Subhas KUNDU (Indian institute of technology, Kharagpur, India)
X-ray diffraction study of epithelial tissue of silk gland of Indian domestic Antheraea mylitta silkworm was carry out on the small-angle station DIKSI of the Siberia-2 storage ring (NRC “Kurchatov institute”, Moscow).
The silk gland is a unique pair organ of internal secretion in diameter 2 mm and length about 1 metre, that ten times surpasses the size of the larva of a silkworm. In an active phase of cocooning all three departments of a glan (anterior, middle, and posterior) are filled by jelly-like substratum from fibroin and sericin proteins which form a silk thread under the influence of mechanical forces (pulling) and specific geometry of keratin segment of gland. Samples of various departments of a silk gland have been allocated from a larva by soft preparation methods, and after that dried up at a room temperature under cargo.
X-ray patterns of all departments of a silk gland are characteristic for epithelial tissues: in a range of 1-5 nm its show several Debay’ rings with the basic period of identity of 4.72 nm. In our earlier investigations of epithelial tissues of animals and human the series of diffraction Debay’ reflections at the spacing of 4.65 (± 0.15) nm were attributed to proteoglycan structures of extracellular matrix [A.Vazina et al.: NIM (2001) A470; NIM (2005) A543; NIM (2009) A603; Glass Phys. Chem. (2007) 33]. Thus, this periodicity is a nanostructural invariant of proteoglycan structures of epithelial tissues of animals, human, and insect also.