Cell surface-associated chondroitin sulfate proteoglycans bind contact phase factor H-kininogen

The kinin system has been recognized as a locally operating hormone system of cardiovascular cells, however, the molecular mechanisms regulating circu mscribed kinin release on cell surfaces are not fully understood. In partic ular, the principal cell docking sites for the kinin precursor, high molecu lar weight kininogen (HK), are not fully explored. Here me demonstrate by e nzymatic digestion, recombinant overexpression, and affinity cross-linking studies that cell surface chondroitin sulfate (CS) chains of proteoglycans (PGs) serve as major HK binding sites on platelet, fibroblast, liver, and e ndothelial kidney cells. In this may, CS-type PGs mar contribute to a local accumulation of kinin precursors on cell surfaces and modulate circumscrib ed release of short-lived kinin hormones at or next to their site of action . (C) 2001 Federation of European Biochemical Societies. Published by Elsev ier Science B.V. All rights reserved.