Chemistry: natural resins or derivatives; peptides or proteins; – Proteins – i.e. – more than 100 amino acid residues
Reexamination Certificate
1999-02-12
2003-03-18
Murthy, Ponnathapuachuta (Department: 1852)
Chemistry: natural resins or derivatives; peptides or proteins;
Proteins, i.e., more than 100 amino acid residues
Reexamination Certificate
active
06534629
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to specific proteins as well as recombinant versions of these proteins which are serine protease inhibitors, including potent anticoagulants in human plasma. These proteins include certain proteins extracted from nematodes. In another aspect, the present invention relates to compositions comprising these proteins, which are useful as potent and specific inhibitors of blood coagulation enzymes in vitro and in vivo, and methods for their use as in vitro diagnostic agents, or as in vivo therapeutic agents, to prevent the clotting of blood. In a further aspect, the invention relates to nucleic acid sequences, including mRNA and DNA, encoding the proteins and their use in vectors to transfect or transform host cells and as probes to isolate certain related genes in other species and organisms.
BACKGROUND AND INTRODUCTION TO THE INVENTION
Normal hemostasis is the result of a delicate balance between the processes of clot formation (blood coagulation) and clot dissolution (fibrinolysis). The complex interactions between blood cells, specific plasma proteins and the vascular surface, maintain the fluidity of blood unless injury occurs. Damage to the endothelial barrier lining the vascular wall exposes underlying tissue to these blood components. This in turn triggers a series of biochemical reactions altering the hemostatic balance in favor of blood coagulation which can either result in the desired formation of a hemostatic plug stemming the loss of blood or the undesirable formation of an occlusive intravascular thrombus resulting in reduced or complete lack of blood flow to the affected organ.
The blood coagulation response is the culmination of a series of amplified reactions in which several specific zymogens of serine proteases in plasma are activated by limited proteolysis. This series of reactions results in the formation of an insoluble matrix composed of fibrin and cellular components which is required for the stabilization of the primary hemostatic plug or thrombus. The initiation and propagation of the proteolytic activation reactions occurs through a series of amplified pathways which are localized to membranous surfaces at the site of vascular injury (Mann, K. G., Nesheim, M. E., Church, W. R., Haley, P. and Krishnaswamy, S. (1990) Blood 76: 1-16. and Lawson, J. H., Kalafatis, M., Stram, S., and Mann, K. G. (1994) J. Biol. Chem. 269: 23357-23366).
Initiation of the blood coagulation response to vascular injury follows the formation of a catalytic complex composed of serine protease factor VIla and the non-enzymatic co-factor, tissue factor (TF)(Rappaport, S. I. and Rao, L. V, M. (1992) Arteriosclerosis and Thrombosis 12: 1112-1121). This response appears to be exclusively regulated by the exposure of subendothelial TF to trace circulating levels of factor VIIa and its zymogen factor VII, following a focal breakdown in vascular integrity. Autoactivation results in an increase in the number of factor VIIa/TF complexes which are responsible for the formation of the serine protease factor Xa. It is believed that in addition to the factor VIIa/TF complex, the small amount of factor Xa which is formed primes the coagulation response through the proteolytic modification of factor IX to factor IX
alpha
which in turn is converted to the active serine protease factor IX
abeta
by the factor VIIa/TF complex (Mann, K. G., Krishnaswamy, S. and Lawson, J. H. (1992)
Sem. Hematology
29: 213-226.). It is factor IXa
beta
in complex with activated factor VIIIa, which appears to be responsible for the production of significant quantities of factor Xa which subsequently catalyzes the penultimate step in the blood coagulation cascade; the formation of the serine protease thrombin.
Factor Xa catalyzes the formation of thrombin following the assembly of the prothrombinase complex which is composed of factor Xa, the non-enzymatic co-factor Va and the substrate prothrombin (factor II) assembled in most cases, on the surface of activated platelets which are adhered at the site of injury (Fuster, V., Badimon, L., Badimon, J. J. and Chesebro, J. H. (1992)
New Engl. J. Med.
326: 310-318). In the arterial vasculature, the resulting amplified “burst” of thrombin generation catalyzed by prothrombinase causes a high level of this protease locally which is responsible for the formation of fibrin and the further recruitment of additional platelets as well as the covalent stabilization of the clot through the activation of the transglutaminase zymogen factor XIII. In addition, the coagulation response is further propagated through the thrombin-mediated proteolytic feedback activation of the non-enzymatic co-factors V and VIII resulting in more prothrombinase formation and subsequent thrombin generation (Hemker, H. C. and Kessels, H. (1991)
Haemostasis
21: 189-196).
Substances which interfere in the process of blood coagulation (anticoagulants) have been demonstrated to be important therapeutic agents in the treatment and prevention of thrombotic disorders (Kessler, C. M. (1991) Chest 99: 97S-112S and Cairns, J. A., Hirsh, J., Lewis, H. D., Resnekov, L., and Theroux, P. (1992) Chest 10: 456S-481S). The currently approved clinical anticoagulants have been associated with a number of adverse effects owing to the relatively non-specific nature of their effects on the blood coagulation cascade (Levine, M. N., Hirsh, J., Landefeld, S., and Raskob, G. (1992) Chest 102: 352S-363S). This has stimulated the search for more effective anticoagulant agents which can more effectively control the activity of the coagulation cascade by selectively interfering with specific reactions in this process which may have a positive effect in reducing the complications of anticoagulant therapy (Weitz, J., and Hirsh, J. (1993) J. Lab. Clin. Med. 122: 364-373). In another aspect, this search has focused on normal human proteins which serve as endogenous anticoagulants in controlling the activity of the blood coagulation cascade. In addition, various hematophageous organisms have been investigated because of their ability to effectively anticoagulate the blood meal during and following feeding on their hosts suggesting that they have evolved effective anticoagulant strategies which may be useful as therapeutic agents.
A plasma protein, Tissue Factor Pathway Inhibitor (TFPI), contains three consecutive Kunitz domains and has been reported to inhibit the enzyme activity of factor Xa directly and, in a factor Xa-dependent manner, inhibit the enzyme activity of the factor VIIa-tissue factor complex. Salvensen,G., and Pizzo, S. V., “Proteinase Inhibitors: &agr;-Macroglobulins, Serpins, and Kunis”, “Hemostasis and Thrombosis, Third Edition, pp. 251-253, J. B. Lippincott Company (Edit. R. W. Colman et al. 1994). A cDNA sequence encoding TFPI has been reported, and the cloned protein was reported to have a molecular weight of 31,950 daltons and contain 276 amino acids. Broze, G. J. and Girad, T. J., U.S. Pat. No. 5,106,833, col. 1, (1992). Various recombinant proteins derived from TFPI have been reported. Girad, T. J. and Broze, G. J., EP 439,442 (1991); Rasmussen, J. S. and Nordfand, O. J., WO 91/02753 (1991); and Broze, G. J. and Girad, T. J., U.S. Pat. No. 5,106,833, col. 1, (1992).
Antistasin, a protein comprised of 119 amino acids and found in the salivary gland of the Mexican leech,
Haementeria officinalis,
has been reported to inhibit the enzyme activity of factor Xa. Tuszynski et al., J. Biol. Chem, 262:9718 (1987); Nutt, et al., J. Biol. Chem, 263:10162 (1988). A 6,000 daltons recombinant protein containing 58 amino acids with a high degree homology to antistasin's amino-terminus amino acids 1 through 58 has been reported to inhibit the enzyme activity of factor Xa. Tung, J. et al., EP 454,372 (Oct. 30, 1991); Tung, J. et al., U.S. Pat. No. 5,189,019 (Feb. 23, 1993).
Tick Anticoagulant Peptide (TAP), a protein comprised of 60 amino acids and isolated from the soft tick,
Ornithodoros moubata,
has been reported to inhibit the enzyme activity of factor Xa but not fac
Bergum Peter W.
Gansemans Yannick Georges Jozef
Jespers Laurent Stephane
LaRoche Yves Rene
Lauwereys Marc Josef
Biggs Suzanne L.
Corvas International Inc.
Murthy Ponnathapuachuta
Pillsbury & Winthrop LLP
Steadman David J
LandOfFree
Nematode-extracted serine protease inhibitors and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Nematode-extracted serine protease inhibitors and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Nematode-extracted serine protease inhibitors and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3001983