Biomaterial Database

The chemistry and biology of thymosin. II. Amino acid sequence analysis of thymosin alpha1 and polypeptide beta1. 1979

T L Low, and A L Goldstein

The amino acid sequences of two polypeptide components of thymosin Fraction 5 termed thymosin alpha1 and polypeptide beta1 have been established. The sequences were determined by automatic Edman degradation of the intact molecules as well as by manual sequence analysis of the enzymatic cleavage products. Thymosin alpha1, an immunologically active polypeptide, is highly acidic with an isoelectric point of 4.2. This molecule is composed of 28 amino acid residues with acetylserine as the NH2 terminus. A chemically synthesized molecule of thymosin alpha1 has been found to be as active as the natural molecule in our bioassay systems. Polypeptide beta1 is a molecule consisting of 74 amino acid residues and has an isoelectric point of 6.7. This peptide is not biologically active in our assay systems, suggesting that it is not involved in thymic hormone action. The sequence of beta1 was found to be identical with ubiquitin and a portion of protein A24, a nuclear chromosomal protein. The relationships among these proteins are discussed.

UI	MeSH Term	Description	Entries
D010446	Peptide Fragments	Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.	Peptide Fragment,Fragment, Peptide,Fragments, Peptide
D002268	Carboxypeptidases	Enzymes that act at a free C-terminus of a polypeptide to liberate a single amino acid residue.	Carboxypeptidase
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013045	Species Specificity	The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.	Species Specificities,Specificities, Species,Specificity, Species
D013947	Thymosin	Thymosin. A family of heat-stable, polypeptide hormones secreted by the thymus gland. Their biological activities include lymphocytopoiesis, restoration of immunological competence and enhancement of expression of T-cell characteristics and function. They have therapeutic potential in patients having primary or secondary immunodeficiency diseases, cancer or diseases related to aging.	Thymosin Fs,Thymosins
D013951	Thymus Hormones	Humoral factors secreted by the thymus gland. They participate in the development of the lymphoid system and the maturation of the cellular immune response.	Thymic Hormones,Hormones, Thymic,Hormones, Thymus
D014357	Trypsin	A serine endopeptidase that is formed from TRYPSINOGEN in the pancreas. It is converted into its active form by ENTEROPEPTIDASE in the small intestine. It catalyzes hydrolysis of the carboxyl group of either arginine or lysine. EC 3.4.21.4.	Tripcellim,Trypure,beta-Trypsin,beta Trypsin
D046911	Macromolecular Substances	Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.	Macromolecular Complexes,Macromolecular Compounds,Macromolecular Compounds and Complexes,Complexes, Macromolecular,Compounds, Macromolecular,Substances, Macromolecular