Thymalin (also known as thymic factor or its old name facteur thymique serique) is a nonapeptide produced by two distinct epithelial populations in the thymus. It requires zinc for biological activity. Its peptide sequence is H-Pyr-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn-OH.The hormone is believed to be involved in T-cell differentiation and enhancement of T and NK cell actions. Besides this rather paracrine or auto-organic effects on the thymus dependent immune system, thymalin seems to have neuroendocrine effects as well. There exist bidirectional interactions between thymic epithelium and the hypothalamus-pituitary axis (for example, thymalin follows a circadian rhythm and physiologically elevated ACTH levels correlate positively with thymalin plasma levels and vice versa).
Molar Mass: 858.85 g/mol