[16] Thymosin β4

Publisher Summary This chapter provides an overview of β 4 . Thymosin β 4 is a polypeptide isolated from thymosin fraction 5 (F5) and fraction 5A (5A). This peptide exhibits important activities in the regulation and differentiation of thymus-dependent lymphocytes. It induces expression of TdT activity in vivo 2 and in vitro. 3 It also inhibits the migration of macrophages, and exerts biological effects on the hypothalamus and pituitary. The chapter further provides purification procedure, thymosin β 4 is present in both thymosin F5 and F5A. However, its relative concentration is higher in F5A than in F5. This peptide can be purified either by conventional column technique or by HPLC. Conventional column techniques are used for large-scale purification, while the HPLC procedure is used when the starting material available is limited. In addition, the chapter also explains purification by HPLC from thymosin F5A or tissue extracts.