scleroprotein One of a group of insoluble, fibrous proteins, which serve as structural materials within the body. The group includes the collagens and keratins.

scleroprotein Any of a group of proteins found in the exoskeletons of some invertebrates, notably insects. Scleroproteins are formed by conversion of the relatively soft elastic larval protein by a natural tanning process (sclerotization) involving orthoquinones. These are secreted and form cross linkages between polypeptides of the proteins, producing a hard rigid covering.