A class of fibrous proteins or scleroproteins that represents the principal constituent of EPIDERMIS; HAIR; NAILS; horny tissues, and the organic matrix of tooth ENAMEL. Two major conformational groups have been characterized, alpha-keratin, whose peptide backbone forms a coiled-coil alpha helical structure consisting of TYPE I KERATIN and a TYPE II KERATIN, and beta-keratin, whose backbone forms a zigzag or pleated sheet structure. alpha-Keratins have been classified into at least 20 subtypes. In addition multiple isoforms of subtypes have been found which may be due to GENE DUPLICATION.

Descriptor ID	D007633
MeSH Number(s)	D05.750.078.593.450 D12.776.220.475.450 D12.776.860.607
Concept/Terms	Keratins Keratins Cytokeratin Keratin Keratin, Glycosylated Keratin, Glycosylated Glycosylated Keratin Keratin-Associated Proteins Keratin-Associated Proteins Keratin Associated Proteins alpha-Keratin alpha-Keratin alpha Keratin

Below are MeSH descriptors whose meaning is more general than "Keratins".

Below are MeSH descriptors whose meaning is related to "Keratins".

Below are MeSH descriptors whose meaning is more specific than "Keratins".