期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1979
卷号：76
期号：4
页码：1986-1989
DOI：10.1073/pnas.76.4.1986
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Previously, we have stablished that the fifth component of complement (C5) serves as an important source of mediators that have locomotory (chemotactic) activity for leukocytes and tumor cells. C5a, a fragment (Mr 11,200) derived from the NH2-terminal portion of the alpha chain of C5, is the major chemotactic peptide for leukocytes. The present studies demonstrate that cleavage of C5a with trypsin generates a derivative peptide that is chemotactic for tumor cells (Walker carcinosarcoma). This fragment has an estimated Mr of 6000 as assessed by gel filtration and does not require the COOH-terminal arginine of C5a, because equivalent amounts of chemotactic activity for tumor cells can be generated from des-Arg-C5a by digestion with trypsin. The C5a-derived chemotactic peptide for tumor cells demonstrates peak activity at approximately 1 pM. These studies emphasize the key role of the C5a region of the C5 molecule in the generation of peptides that affect locomotory responses of cells.
