A simplified method for purification of human C5a from citrated plasma.

A simplified immunoadsorption technique has been developed to purify human C5a. the 11 000 Da glycopeptide produced by C5 convertase cleavage of the fifth component of complement. In this method, human C5 fragments, including C5a, are isolated from zymosan-activated plasma by affinity chromatography, concentrated on CM 52 cellulose, and then purified to homogeneity by gel filtration on Sephadex G-75 in phosphate-buffered saline. Human C5a prepared by this technique demonstrates characteristic immunochemical and biological activity. This method has also been adapted for the purification of 125I-C5a in phosphate-buffered saline. This technique offers a simplified approach to the purification of this important soluble mediator of inflammation.