Peptide sequence: YDLKTETAPL VVVVSTTGTG DPPDTARKFV KEIQNQTLPV DFFAHLRYGL Sequence homology: Cow: 93%; Dog: 100%; Guinea Pig: 93%; Horse: 93%; Human: 100%; Mouse: 100%; Pig: 100%; Rabbit: 100%; Rat: 100%. Methionine is an essential amino acid required for