Abstract: Methods for converting prethrombin-1 to thrombin are disclosed. An aqueous solution of prethrombin-1 is applied to oscutarin-C immobilized on a solid support so as to provide from 500 mg to 4000 mg of prethrombin-1 per mL of the solid support and a contact time between the prethrombin-1 and the oscutarin-C of from 1.8 to 3.5 minutes. The resulting active thrombin may be captured on an ion exchange chromatography medium or an affinity chromatography medium.

Abstract: Methods for converting prethrombin-1 to thrombin are disclosed. An aqueous solution of prethrombin-1 is applied to oscutarin-C immobilized on a solid support so as to provide from 500 mg to 4000 mg of prethrombin-1 per mL of the solid support and a contact time between the prethrombin-1 and the oscutarin-C of from 1.8 to 3.5 minutes. The resulting active thrombin may be captured on an ion exchange chromatography medium or an affinity chromatography medium.

Abstract: Purified mammalian thrombopoietin proteins and methods of making them are disclosed. The proteins are characterized by a M.sub.r =70,000.+-.10,000 daltons as determined by SDS-polyacrylamide gel electrophoresis under denaturing conditions and are at least 90% pure with respect to contaminating proteins. The proteins can be prepared by a method in which thrombopoietin is adsorbed to and eluted from a polypeptide comprising a ligand-binding domain of an MPL receptor, then the eluted thrombopoietin is fractionated by anion exchange chromatography.

Abstract: Methods for identifying factors that regulate appetite are disclosed. Preferably, the methods feature determinination of decreased food consumption in selected recipient mammals following administration of a test sample. A product having appetite suppressing activity is also described. In addition, methods for reducing food consumption in a mammal, featuring administration of a pharmaceutical composition comprising a representative appetite suppression factor, are disclosed.

Abstract: Methods for determining ob protein in a biological sample are disclosed. In a preferred embodiment, the biological samples are analyzed using an ELISA capable of detecting and quantitating ob protein.

Abstract: Methods of removing protein contaminants from a solution comprising thrombopoietin are disclosed. The solution is exposed to hydroxyapatite, whereby protein contaminants are bound to the hydroxyapatite and the thrombopoietin remains substantially unbound, and the unbound thrombopoietin is recovered. The use of hydroxyapatite is advantageously combined with other purification and concentration techniques, including ion-exchange chromatography, ligand affinity chromatography, hydrophobic interaction chromatography, ultrafiltration, and differential precipitation.

Abstract: Substantially pure porcine proteins having chemoattractant activity for neutrophils and methods for preparing the proteins are provided. These proteins are useful within compositions for enhancing neutrophil chemotaxis, such as in promoting the formation of granulation tissue. The proteins may also be used within methods for developing inflammatory and anti-inflammatory agents.