Fibrous proteins, also called scleroproteins, are one of the two main classes of protein quaternary structure (the other being globular proteins). Fibrous proteins are only found in animals.
Fibrous proteins from long protein filaments, rod- or wire-like shapes. They are usually inert structural or storage proteins. They are generally water-insoluble and are found as an aggregate due to hydrophobicR groups that stick out of the molecule. The amino acid sequences they are made from often have limited residues with repeats. These can form unusual secondary structures, e.g. collagen triple helix. The structures often contain 'cross-links' between chains, for example cys-cys disulfide bonds between keratin chains.
Globular proteins tend to denature more easily than fibrous proteins.
