P. C. Harpel

Homocysteine and other sulfhydryl compounds enhance the binding of lipoprotein(a) to fibrin: a potential biochemical link between thrombosis, atherogenesis, and sulfhydryl compound metabolism.

Harpel, P C, Chang, V T, Borth, W

We have previously shown that lipoprotein(a) [Lp(a)], an atherogenic lipoprotein that contains apolipoprotein(a), which shares partial structural homology to plasminogen, binds to a plasmin-modified...

Plasmin catalyzes binding of lipoprotein (a) to immobilized fibrinogen and fibrin.

Harpel, P C, Gordon, B R, Parker, T S

Lipoprotein (a) [Lp(a)] is a plasma component whose concentration is related to the development of atherosclerosis, although the underlying mechanisms are not known. Lp(a) contains a unique...

Studies on human plasma C1 inactivator-enzyme interactions. I. Mechanisms of interaction with C1s, plasmin, and trypsin.

Harpel, P C, Cooper, N R

This study has explored the nature of the molecular events which occur when C1 inactivator, a human plasma inhibitor of the complement, kinin-forming, coagulation, and fibrinolytic enzyme systems,...

Studies on human plasma C1 inactivator-enzyme interactions. II. Structural features of an abnormal C1 inactivator from a kindred with hereditary angioneurotic edema.

Harpel, P C, Hugli, T E, Cooper, N R

The function and several of the structural features of the C1 inactivator protein isolated from the plasma of a mother and daughter with the variant form of hereditary angioneurotic edema have been...

A common neoepitope is created when the reactive center of C1-inhibitor is cleaved by plasma kallikrein, activated factor XII fragment, C1 esterase, or neutrophil elastase.

De Agostini, A, Patston, P A, Marottoli, V, Carrel, S, Harpel, P C, Schapira, M

The reactive center of C1-inhibitor, a plasma protease inhibitor that belongs to the serpin superfamily, is located on a peptide loop which is highly susceptible to proteolytic cleavage. With plasma...

Aspirin inhibits vascular plasminogen activator activity in vivo. Studies utilizing a new assay to quantify plasminogen activator activity.

Levin, R I, Harpel, P C, Weil, D, Chang, T S, Rifkin, D B

Vascular or tissue-type plasminogen activator (TPA) is a key enzyme in physiologic fibrinolysis. To study the role of prostaglandins in modulating the synthesis and release of TPA in vivo, we...

Alpha2-plasmin inhibitor and alpha2-macroglobulin-plasmin complexes in plasma. Quantitation by an enzyme-linked differential antibody immunosorbent assay.

Harpel, P C

An enzyme-linked differential antibody immunosorbent assay has been developed for the quantification of alpha2-plasmin inhibitor-plasmin and alpha2-macroglobulin-plasmin complexes. In this method the...

Complex formation of platelet thrombospondin with histidine-rich glycoprotein.

Leung, L L, Nachman, R L, Harpel, P C

Thrombospondin and histidine-rich glycoprotein are two proteins with diverse biological activities which have been associated with human platelets and other cell systems. Using an enzyme-linked...

Complex formation of platelet thrombospondin with plasminogen. Modulation of activation by tissue activator.

Silverstein, R L, Leung, L L, Harpel, P C, Nachman, R L

Thrombospondin (TSP), a multifunctional alpha-granule glycoprotein of platelets, binds fibrinogen, fibronectin, heparin, and histidine-rich glycoprotein and thus may play an important role in...

Platelet thrombospondin forms a trimolecular complex with plasminogen and histidine-rich glycoprotein.

Silverstein, R L, Leung, L L, Harpel, P C, Nachman, R L

Thrombospondin (TSP), a multifunctional alpha-granule glycoprotein of human platelets binds fibrinogen, fibronectin, heparin, histidine-rich glycoprotein (HRGP), and plasminogen (Plg), and thus, may...

Plasminogen activator inhibitor is associated with the extracellular matrix of cultured bovine smooth muscle cells.

Knudsen, B S, Harpel, P C, Nachman, R L

The extracellular matrix secreted by cultured bovine smooth muscle cells (BSMC) contains an endothelial type plasminogen activator (PA) inhibitor. When PA is incubated with the matrix, a high...

Binding of tissue plasminogen activator to cultured human endothelial cells.

Hajjar, K A, Hamel, N M, Harpel, P C, Nachman, R L

Tissue plasminogen activator (t-PA) and urokinase (u-PA), the major activators of plasminogen, are synthesized and released from endothelial cells. We previously demonstrated specific and functional...

The atherogenic lipoprotein Lp(a) is internalized and degraded in a process mediated by the VLDL receptor.

Argraves, K M, Kozarsky, K F, Fallon, J T, Harpel, P C, Strickland, D K

Lp(a) is a major inherited risk factor associated with premature heart disease and stroke. The mechanism of Lp(a) atherogenicity has not been elucidated, but likely involves both its ability to...

Homocysteine and other sulfhydryl compounds enhance the binding of lipoprotein(a) to fibrin: a potential biochemical link between thrombosis, atherogenesis, and sulfhydryl compound metabolism.

Harpel, P C, Chang, V T, Borth, W

We have previously shown that lipoprotein(a) [Lp(a)], an atherogenic lipoprotein that contains apolipoprotein(a), which shares partial structural homology to plasminogen, binds to a plasmin-modified...

Plasmin catalyzes binding of lipoprotein (a) to immobilized fibrinogen and fibrin.

Harpel, P C, Gordon, B R, Parker, T S

Lipoprotein (a) [Lp(a)] is a plasma component whose concentration is related to the development of atherosclerosis, although the underlying mechanisms are not known. Lp(a) contains a unique...

Studies on human plasma C1 inactivator-enzyme interactions. I. Mechanisms of interaction with C1s, plasmin, and trypsin.

Harpel, P C, Cooper, N R

This study has explored the nature of the molecular events which occur when C1 inactivator, a human plasma inhibitor of the complement, kinin-forming, coagulation, and fibrinolytic enzyme systems,...

Studies on human plasma C1 inactivator-enzyme interactions. II. Structural features of an abnormal C1 inactivator from a kindred with hereditary angioneurotic edema.

Harpel, P C, Hugli, T E, Cooper, N R

The function and several of the structural features of the C1 inactivator protein isolated from the plasma of a mother and daughter with the variant form of hereditary angioneurotic edema have been...

A common neoepitope is created when the reactive center of C1-inhibitor is cleaved by plasma kallikrein, activated factor XII fragment, C1 esterase, or neutrophil elastase.

De Agostini, A, Patston, P A, Marottoli, V, Carrel, S, Harpel, P C, Schapira, M

The reactive center of C1-inhibitor, a plasma protease inhibitor that belongs to the serpin superfamily, is located on a peptide loop which is highly susceptible to proteolytic cleavage. With plasma...

Aspirin inhibits vascular plasminogen activator activity in vivo. Studies utilizing a new assay to quantify plasminogen activator activity.

Levin, R I, Harpel, P C, Weil, D, Chang, T S, Rifkin, D B

Vascular or tissue-type plasminogen activator (TPA) is a key enzyme in physiologic fibrinolysis. To study the role of prostaglandins in modulating the synthesis and release of TPA in vivo, we...

Alpha2-plasmin inhibitor and alpha2-macroglobulin-plasmin complexes in plasma. Quantitation by an enzyme-linked differential antibody immunosorbent assay.

Harpel, P C

An enzyme-linked differential antibody immunosorbent assay has been developed for the quantification of alpha2-plasmin inhibitor-plasmin and alpha2-macroglobulin-plasmin complexes. In this method the...

Complex formation of platelet thrombospondin with histidine-rich glycoprotein.

Leung, L L, Nachman, R L, Harpel, P C

Thrombospondin and histidine-rich glycoprotein are two proteins with diverse biological activities which have been associated with human platelets and other cell systems. Using an enzyme-linked...

Complex formation of platelet thrombospondin with plasminogen. Modulation of activation by tissue activator.

Silverstein, R L, Leung, L L, Harpel, P C, Nachman, R L

Thrombospondin (TSP), a multifunctional alpha-granule glycoprotein of platelets, binds fibrinogen, fibronectin, heparin, and histidine-rich glycoprotein and thus may play an important role in...

Platelet thrombospondin forms a trimolecular complex with plasminogen and histidine-rich glycoprotein.

Silverstein, R L, Leung, L L, Harpel, P C, Nachman, R L

Thrombospondin (TSP), a multifunctional alpha-granule glycoprotein of human platelets binds fibrinogen, fibronectin, heparin, histidine-rich glycoprotein (HRGP), and plasminogen (Plg), and thus, may...

Plasminogen activator inhibitor is associated with the extracellular matrix of cultured bovine smooth muscle cells.

Knudsen, B S, Harpel, P C, Nachman, R L

The extracellular matrix secreted by cultured bovine smooth muscle cells (BSMC) contains an endothelial type plasminogen activator (PA) inhibitor. When PA is incubated with the matrix, a high...

Binding of tissue plasminogen activator to cultured human endothelial cells.

Hajjar, K A, Hamel, N M, Harpel, P C, Nachman, R L

Tissue plasminogen activator (t-PA) and urokinase (u-PA), the major activators of plasminogen, are synthesized and released from endothelial cells. We previously demonstrated specific and functional...

The atherogenic lipoprotein Lp(a) is internalized and degraded in a process mediated by the VLDL receptor.

Argraves, K M, Kozarsky, K F, Fallon, J T, Harpel, P C, Strickland, D K

Lp(a) is a major inherited risk factor associated with premature heart disease and stroke. The mechanism of Lp(a) atherogenicity has not been elucidated, but likely involves both its ability to...

C1 inactivator-C1s complexes in inflammatory joint disease.

Inman, R D, Harpel, P C

A newly developed enzyme linked immunosorbent assay for the quantitation of C1 inhibitor (C1In)-C1s complexes was used to study activation of the classical pathway of complement in inflammatory joint...

Oxidation of apolipoprotein(a) inhibits kringle-associated lysine binding: the loss of intrinsic protein fluorescence suggests a role for tryptophan residues in the lysine binding site.

Hermann, A., Laws, W. R., Harpel, P. C.

Lipoprotein(a) [Lp(a)] is a low-density lipoprotein complex consisting of apolipoprotein(a) [apo(a)] disulfide-linked to apolipoprotein B-100. Lp(a) has been implicated in atherogenesis and...

Lipoprotein(a): searching for a function.

Harpel, P. C., Poon, M., Zhang, X., Taubman, M. B.