Ralph Pannell

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The regulation of plasmin generation on cell surfaces is of critical importance in the control of vascular homeostasis. Cell-derived microparticles participate in the dissemination of biological activities. However, their capacity to promote plasmin generation has not been documented. In this study, we show that endothelial microparticles (EMPs) from tumor(More)
The dye Cibacron Blue F-3-GA was conjugated to Sepharose to provide an affinity column for serum albumin. Passage of whole human plasma through a column of Cibacron Blue-Sepharose results in the removal of approx. 98% of the albumin. The latter can be quantitatively recovered by desorption with NaSCN. Albumin-depleted plasma can be readily resolved into(More)
We are studying the biosynthesis and processing of acid hydrolases from Dictyostelium discoideum. We prepared antibody to highly purified alpha-mannosidase from the spent medium of stationary phase cultures. It precipitated alpha-mannosidase but not beta-hexosaminidase, alpha-glucosidase, beta-glucosidase, or any of the major proteins in cell lysates or(More)
Tissue plasminogen activator (t-PA) and/or pro-urokinase (pro-UK) induced lysis of standard 125I-fibrin clots suspended in plasma was studied. Doses were kept below the concentration at which a nonspecific effect was seen, i.e., where fibrinogenolysis and major plasminogen consumption were observed. Small amounts of t-PA potentiated clot lysis by pro-UK by(More)
When single-chain pro-UK is activated by plasmin or kallikrein, the Lys158-Ile159 bond is cleaved, leaving a C-terminal lysine on the A-chain (Lys-UK). Two-chain, high molecular weight urokinase (UK) purified from urine, however, has been shown to contain a phenylalanine residue as the C-terminal of the A-chain (Phe-UK). Since C-terminal lysine residues(More)
BACKGROUND Prourokinase (prouPA) is unstable in plasma at therapeutic concentrations. A mutant form, M5, made more stable by reducing its intrinsic activity was therefore developed. Activation to two-chain M5 (tcM5) induced a higher catalytic activity than two-chain urokinase plasminogen activator (tcuPA), implicating an active site functional difference.(More)
BACKGROUND A single site mutant (M5) of prourokinase (proUK) was developed to make proUK less vulnerable to spontaneous activation in plasma. This was a problem that seriously compromised proUK in clinical trials, as it precluded proUK-mediated fibrinolysis at therapeutic concentrations. METHODS AND RESULTS After completing dose-finding studies, 12(More)
A single-chain 55,000-mol wt form of urokinase (UK), similar to that previously isolated from urine, was purified from a transformed kidney cell culture medium and characterized; and its fibrinolytic properties were evaluated. The preparation immunoprecipitated with UK antiserum, had a low intrinsic amidolytic activity that was 0.1% of its active(More)