Novel Anticoagulation Peptide(s)
1 R43 HL52444-1,
This study will develop a new anti-thrombotic drugs for the treatment of thromboembolicdisorders. In pilot studies, a coagulation inhibitor has been identified in an aqueous extract of Anodontiawoodiana. Early chromatographic and spectral data suggest that the active principle(s) may be a smallpeptide with a molecular weight range between 2,000-4,000 Daltons. Active fractions from thispreparation block thrombin activity and can also prolong the prothrombin and thrombin timemeasurements. This application will obtain support to further purify the active component(s) of theaqueous extract. Its physical, chemical and biological activities will then be evaluated with an eventualgoal of elucidation of the mode of action of this new compound. In the Phase I study, totalcharacterization of the active component of the extract is anticipated and this will be followed by PhaseII development of the antithrombotic principle with eventual entry into clinical research. The majorinterest in Thrombo Diagnostic is to develop remedies from herbs and animal sources which haveminimal side effects. Such compounds have been used in China for more than a thousand years. Thereis an extract from clam (A. woodiana) which has been used in China for thrombotic disorders. Clamshells are ground and extracted in acetic acid in the cold for 2 hours. After filtration, centrifugation anddialysis of the supernatant, a compound is obtained which prolongs the activated partial thromboplastintime (66 seconds as compared to a control of 26-30 seconds) (at a concentration of 50 ug/ml). Ionexchange chromatography, starting with QAE-Sephadex has been carried out and an active fractioneluted in the first peak. Further purification was done on a mono-Q column with FPLC. A UV spectrumshows a single or several related peptides. The fraction is trypsin-sensitive, but pepsin insensitive. Inaddition to activity in coagulation tests as mentioned, the compound inhibits alpha-thrombin. Thus, themajor fraction may be a thrombin inhibitor. The compound is different from Hirudin and may representa new class antithrombin-type anticoagulants. It is not thought to be a degradation product of anotherlarger protein. In this Phase I application, a larger number of separation techniques will be used to purifythe compound to homogeneity. This will involve additional types of chromatography which shouldresolve the material into a single component. The active fraction contains mostly polar molecules whichare hydrophobic and is already quite pure. Thus, further chromatography may resolve the components.Structural studies are also anticipated, including nuclear magnetic resonance spectroscopy. Dr. AlfredWeinheimer, a medicinal chemist who is Chairman of the College of Pharmacy at the University ofHouston will act as a consultant as will Dr. Kenneth K. Wu, who is a world authority in the coagulationfield. Questions to be asked include whether the compound binds to a site on thrombin which is similarto hirudin or to AT-III. Tests will also be carried out to learn whether the compound blocks activatedfactor X. If the final product contains more than one compound, these may have distinct anticoagulantproperties. On the other hand, a single component may have multiple inhibitory properties. Specificcoagulation factor assays will be carried out to determine the above mentioned details.
Small Business Information at Submission:
Principal Investigator:Sudershan Sanduja
Box 270671 Houston, TX 77277
Number of Employees: