HUMAN-COMPLEMENT FACTOR-B - FUNCTIONAL-PROPERTIES OF A RECOMBINANT ZYMOGEN OF THE ALTERNATIVE ACTIVATION PATHWAY CONVERTASE

The human complement factor B is a centrally important component of th e alternative pathway activation of the complement system. Here we rep ort the isolation, characterization and eukaryotic expression of the f irst full length cDNA transcript for human factor B. In a factor B dep endent haemolysis assay, the recombinant human factor B generated by t ransient COS cell transfection was shown to reconstitute haemolytic ac tivity of factor B depleted human serum. To study the biological activ ities assigned to factor B, the availability of recombinant polypeptid es representing definite portions of the human factor B molecule is de sirable.