Function
While DSIP was originally described for inducing spindle and delta sleep activity when infused into the brain of rabbits; later studies report stress-modulating and endocrine effects, though its physiological role is still debated47, Thymosin Alpha-1 is clinically used in some countries as an immunomodulator for chronic hepatitis B/C and as an adjuvant in cancer therapy, enhancing cell-mediated immunity41487.
Mechanism
While DSIP works as an endogenous nonapeptide, Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu, with proposed neuromodulatory actions; it interacts with components of the MAPK cascade and may be related to glucocorticoid-induced leucine zipper (GILZ), but its precise biosynthetic origin remains unknown4757, Thymosin Alpha-1 is a 28-amino-acid thymic peptide fragment of prothymosin alpha that activates dendritic cells and T cells primarily via TLR9/MyD88/NF-κB signaling, enhancing Th1 responses and NK-cell cytotoxicity414.
Length and Sequence
DSIP is 9 amino acids long, whereas Thymosin Alpha-1 is longer as it has a length of 28 amino acids. DSIP is made up of a sequence of Tryptophan, Alanine, Glycine, Glycine, Aspartic acid, Alanine, Serine, Glycine, Glutamic acid. Thymosin Alpha-1 is made up of a sequence of Serine, Aspartic acid, Alanine, Alanine, Valine, Aspartic acid, Threonine, Serine, Serine, Glutamic acid, Isoleucine, Threonine, Threonine, Lysine, Aspartic acid, Leucine, Lysine, Glutamic acid, Lysine, Lysine, Glutamic acid, Valine, Valine, Glutamic acid, Glutamic acid, Alanine, Glutamic acid, Asparagine.