Lectin Lectin Lectins are carbohydrate-binding proteins, macromolecules that are highly specific for sugar moieties of other molecules. Lectins perform recognition on the cellular and molecular level and play numerous roles in biological recognition phenomena involving cells, carbohydrates, and proteins. Lectins also mediate attachment and binding of bacteria and viruses to their intended targets. Lectins are ubiquitous in nature and are found in many foods. Some foods such as beans and grains need to be cooked or fermented to reduce lectin content. Some lectins are beneficial, such as CLEC11A which promotes bone growth, while others may be powerful toxins such as ricin.
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