The amino acid sequence of a biologically active polypeptide isolated from calf thymus, termed thymosin al, has been determined. Thymosin a, is a heat stable, highly acidic molecule composed of 28 amino acid residues. This peptide is one of several present in thymosin fraction 5 that may participate in the regulation, differentiation, and function of thymus-dependent lymphocytes (T cells). A nomenclature for the family of polypeptides present in thymosin fraction 5 is suggested.
Carrot phosphodiesterase has been purified by a modified procedure until homogeneous, using disc gel electrophoresis, immunoelectrophoresis, and sedimentation in the ultracentrifuge as criteria. The preparation is 1300 times as active as the crude extract representing a threefold increase in specific activity over the material previously described.The overall yield has also been improved to 3 0 x . The enzyme is free from nonspecific phosphatases and 5 '-nucleotidase. Endonuclease activity has been reduced to barely detectable
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.