Identification of human thymus-leukemia-associated antigen as a low-molecular-weight form of adenosine deaminase.
In the determination of whether human thymus-leukemia-associated antigen (HThy-L) is a low-molecular-weight form of adenosine deaminase (ADA), both HThy-L and ADA were found to have the same molecular weight of 45,000 as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The antigen and enzyme displayed a phenomenon of complete identity in immunodiffusion and a high degree of cross-reaction in a competitive radioimmunoassay for HThy-L or ADA. When tested for adenosine-deaminating activity, HThy-L was nearly as active as purified low-molecular-weight ADA from erythrocytes. However, HThy-L and ADA differed in their capacity to combine with the complexing protein isolated from human kidney. Apparently, HThy-L represents a thymic isoenzyme of ADA and is the first antigen to be associated with differentiation of hematopoietic cells for which a functional activity is established.
D000243:Adenosine Deaminase / Q000032:analysis; D000951:Antigens, Neoplasm / Q000032:analysis*; D055598:Chemical Phenomena; D002621:Chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000201:enzymology; D006801:Humans; D005779:Immunodiffusion; D007527:Isoenzymes / Q000032:analysis; D007938:Leukemia / Q000032:analysis / Q000201:enzymology / Q000276:immunology*; D008970:Molecular Weight; D009700:Nucleoside Deaminases / Q000032:analysis; D011863:Radioimmunoassay; D013950:Thymus Gland / Q000032:analysis* / Q000201:enzymology / Q000276:immunology
D000951:Antigens, Neoplasm; D007527:Isoenzymes; D009700:Nucleoside Deaminases; D000243:Adenosine Deaminase