Isolation and Identification of a New Thymic Peptide from Calf Thymus

Xi-Ming Qin, Ming-Xing Duan^*, Bin Deng, Xi-Cheng Liu, Qiang-Zhe Zhang, Zheng Liu, and Hong-Xuan He

State Key Laboratory of Biomembranes and Membrane Biotechnology, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084, China; fax: 086-10-6277-3255; E-mail: duanmx@mail.tsinghua.edu.cn

^* To whom correspondence should be addressed.

Received January 13, 2004; Revision received February 20, 2004

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Various thymic peptides (including thymulin, thymic humoral factor, thymopoietin, etc.) play important roles in the process of T cell maturation and development. We isolated a new peptide from calf thymus and named it thymus activity factor II (TAF-II). A yield of 0.92 mg of TAF-II was purified from 500 g calf thymus. Analysis by LC/MSD-Trap showed the amino acid sequence of this hexapeptide to be Glu-Ala-Lys-Ser-Gln-Gly-OH with molecular weight 618.5 daltons. We have also begun to investigate the influence of TAF-II.

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KEY WORDS: thymus, TAF-II, E-rosette assay, thymic peptide

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