The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 13, 1992
Filed:
Nov. 16, 1989
Robert D Rosenberg, Brookline, MA (US);
Massachusetts Institute of Technology, Cambridge, MA (US);
Abstract
A megakaryocyte stimulatory factor (MSF), purified to homogeneity, is an acidic protein (pI=5.1) with an Mr=15,000 which stimulates PF4-like protein synthesis in rat promegakaryoblast cells by as much as 7-fold, and exhibits half-maximal activity at a concentration of 0.8 pM. MSF exhibits no biologic activity corresponding to other known hemopoietic growth factors, and appears to be specific for the megakaryocyte lineage. In the given examples, MSF was purified to homogeneity (as judged by SDS-PAGE and isoelectric focusing in the presence of 9.2 M urea) from serum-free conditioned medium obtained from cultured human embryonic kidney (HEK) cells, and to near homogeneity from thrombocytopenic plasma. The MSF is isolated by precipitating the MSF with ammonium sulfate at 80% saturation, removing insoluble, non-MSF material and applying the soluble protein to a WGA-Sepharose column, eluting the MSF protein with chitin oligosaccharides, applying the concentrated eluant containing MSF activity to a Biogel P200 column, and chromatographing the eluted MSF fractions on a TSK-G3000 HPLC size exclusion column.