Galactose binding lectin domain Galactose binding lectin domain In molecular biology, the galactose binding lectin domain is a protein domain. It is found in many proteins including the lectin purified from sea urchin ("Anthocidaris crassispina") eggs, SUEL. This lectin exists as a disulfide-linked homodimer of two subunits; the dimeric form is essential for hemagglutination activity. The sea urchin egg lectin (SUEL) forms a new class of lectins. Although SUEL was first isolated as a D-galactoside binding lectin, it was later shown that it binds to L-rhamnose preferentially. L-rhamnose and D-galactose share the same hydroxyl group orientation at C2 and C4 of the pyranose ring
Alpha-keratin of most biological importance of alpha-keratin is its structural stability. When exposed to mechanical stress, α-keratin structures can retain their shape and therefore can protect what they surround. Under high tension, alpha-keratin can even change into beta-keratin, a stronger keratin formation that has a secondary structure of beta-pleated sheets. Alpha-keratin tissues also show signs of viscoelasticity, allowing them to both be able to stretch and absorb impact to a degree, though they are not impervious to fracture. Alpha-keratin strength is also affected by water content in the intermediate filament matrix; higher water content decreases the strength and stiffness of the