How many amino acids are in the protein Keratin?

Vaibhav Bhatt's answer is informative but does not address the actual question. Even restricting the question to humans there are 54 known keratin genes, with molecular weights ranging from 42,000 to 68,000 Da. These MW's would correspond to a range of ~380 to ~620 amino acids. read more

Vaibhav Bhatt’s answer is informative but does not address the actual question. Even restricting the question to humans there are 54 known keratin genes, with molecular weights ranging from 42,000 to 68,000 Da. read more

Among the 18 amino acids that create the keratin molecule, a sulfurous amino acid called cysteine is the most common. In human hair, for example, cysteine composes about 14 percent of keratin. Keratin coils connect by both weak hydrogen bonds and by stronger ionic or sulfide bonds. read more