Partial purification and characterization of contact activation cofactor.

The Journal of Clinical Investigation
S Schiffman, P Lee

Abstract

The contact phase of intrinsic clotting involves Factor XI, Factor XII, Fletcher factor, and a fourth activity that we call contact activation cofactor (CAC). All four of these activities are reduced or absent in Dicalite-adsorbed plasma. A modified activated partial thromboplastin time assay for CAC has been defined by using a substrate of Dicalite-adsorbed plasma combined with partially purified sources of Factors XI and XII, and Fletcher factor. The following properties of CAC in plasma have been determined by using the assay: it is stable up to 60 min at 56 degrees C; gradually loses activity at 80 degrees C; is stable between pH 6 and 9; is precipitated by ammonium sulfate between 40% and 50% saturation; is slightly adsorbed by A1(OH)3; and is eluted from DEAE-cellulose after the major protein peaks. A purification procedure has been devised that separates CAC from other known clotting factors. Isolated CAC was less stable than CAC in plasma, but in the presence of dilute human serum albumin it retained full activity for 80 min at 56 degrees C. On gel filtration CAC had an apparent mol wt of 220,000 daltons. These properties are consistent with those described for Fitzgerald factor, which further supports the conclusion th...Continue Reading

References

Apr 26, 1975·Lancet·R WaldmannO D Ratnoff
May 1, 1975·Thrombosis Research·S SchiffmanR Waldmann
Dec 1, 1972·The Journal of Experimental Medicine·A P Kaplan, K F Austen
Sep 1, 1974·The Journal of Clinical Investigation·S D RevakT E Hugli
Feb 1, 1970·British Journal of Haematology·W E Hathaway, J Alsever
Jul 14, 1969·JAMA : the Journal of the American Medical Association·L H GreenbergY S Wong
Dec 1, 1960·Proceedings of the Society for Experimental Biology and Medicine·S SCHIFFMANJ W MEHL

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Citations

Jan 1, 1986·Critical Reviews in Oncology/hematology·R W Colman, A H Schmaier
Aug 1, 1976·Proceedings of the National Academy of Sciences of the United States of America·J H Griffin, C G Cochrane
Oct 1, 1977·Proceedings of the National Academy of Sciences of the United States of America·R C WigginsJ H Griffin
Apr 1, 1978·Proceedings of the National Academy of Sciences of the United States of America·J H Griffin
Oct 1, 1979·Proceedings of the National Academy of Sciences of the United States of America·R E ThompsonA P Kaplan
Feb 1, 1979·Proceedings of the National Academy of Sciences of the United States of America·O D Ratnoff, H Saito
Dec 1, 1992·Proceedings of the National Academy of Sciences of the United States of America·C F Scott, R W Colman
Jan 1, 1992·The Journal of Cell Biology·S AsakuraD F Mosher
Dec 1, 1976·The Journal of Experimental Medicine·C BiancoZ A Cohn
Dec 1, 1977·The Journal of Clinical Investigation·R E ThompsonA P Kaplan
May 1, 1975·Thrombosis Research·S SchiffmanR Waldmann
Sep 1, 1981·British Journal of Haematology·A JacobsS Schiffman
Feb 1, 1984·British Journal of Haematology·C MannhalterE Deutsch
Jan 1, 1981·Annals of the New York Academy of Sciences·R W ColmanC F Scott
Jul 15, 1983·Thrombosis Research·E DeutschH Rainer

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