Immunochemical studies on thymosin: radioimmunoassay of thymosin beta 4.
Thymosin beta 4, a peptide with hormonal-like properties first isolated from the thymus gland, can be measured in serum using a newly described radioimmunoassay. The radioimmunoassay utilizes an antibody raised in rabbits against synthetic thymosin beta 4 conjugated by glutaraldehyde to keyhole limpet hemocyanin. A 125I-tyrosine-C13 analogue of the biologically active C-terminal fragment is used as the radioactive tracer. The radioimmunoassay is sensitive in the nanogram range and no cross-reactivity with common serum proteins is demonstrable. High performance liquid chromatography of serum samples indicates that two thymosin beta 4 cross-reactive species are present in human serum. Levels in serum range from 450 to 1100 ng/ml and decline with age.
D000595:Amino Acid Sequence; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003429:Cross Reactions; D005312:Fetal Blood / Q000032:analysis; D006801:Humans; D007106:Immune Sera / Q000032:analysis; D011817:Rabbits; D011863:Radioimmunoassay; D013947:Thymosin / Q000031:analogs & derivatives* / Q000032:analysis / Q000097:blood; D000099201:Thymosin beta(4)
D007106:Immune Sera; D013947:Thymosin; D000099201:Thymosin beta(4)