Gla domains as therapeutic agents
The disclosure relates to the recombinant Gla domain proteins and their use targeting phosphatidylserine (PtdS) moieties on the surface of cells, particularly those expressing elevated levels of PtdS, such as cells undergoing apoptosis.
1 . A diagnostic probe molecule for detection of apoptosis by targeting phosphatidylserine cell-surface expression in vivo, said probe molecule comprising:
a polypeptide comprising a protein S gamma-carboxyglutamic-acid (Gla) domain and a protein S Epidermal Growth Factor (EGF) domain, and wherein the polypeptide is fused to a proteinaceous sequence comprising a detectable label or a proteinaceous sequence conjugated to a detectable label;
wherein said probe molecule does not contain a serine protease domain from a Gla domain protein and also does not contain a hormone-binding domain from a Gla domain protein; and
wherein said polypeptide comprises SEQ ID NO: 6 or a derivative differing therefrom only in the absence of the His-tag.
2 . The diagnostic probe molecule according to claim 1 , wherein the polypeptide is 300 amino acids or less.
3 . The diagnostic probe molecule according to claim 1 , wherein the polypeptide comprises SEQ ID NO:6.
4 . The diagnostic probe molecule according to claim 1 , wherein the fused proteinaceous sequence comprises an Fc region.
5 . The diagnostic probe molecule according to claim 1 , wherein the detectable label is selected from the group consisting of a fluorescent label, a chemiluminescent label, a radiolabel, an enzyme, a dye, a ligand, a hapten, a phosphorescent molecule, a chromophore, a photoaffinity molecule, a colored particle, a NMR-detectable substance, and an X-ray imaging agent.
6 . The diagnostic probe molecule according to claim 1 , wherein the label is conjugated to said fused proteinaceous sequence.
7 . A pharmaceutical composition comprising the diagnostic probe molecule of claim 1 and a pharmaceutically acceptable carrier or aqueous medium.
8 . The diagnostic probe molecule according to claim 1 wherein the label is a paramagnetic ion selected from chromium (III), manganese (II), iron (III), iron (II), cobalt (II), nickel (II), copper (II), neodymium (III), samarium (III), ytterbium (III), gadolinium (III), vanadium (II), terbium (III), dysprosium (III), holmium (III) erbium (III), and combinations thereof.
9 . The diagnostic probe molecule according to claim 1 wherein the label is a radioactive isotope selected from astatine 211 , 14 carbon, 51 chromium, 36 chlorine, 57 cobalt, 58 cobalt, copper 67 , 152 Eu, gallium 67 , 3 hydrogen, iodine 123 , iodine 125 , iodine 131 , indium 111 , 59 iron, 32 phosphorus, rhenium 186 , rhenium 188 , 75 selenium, 35 sulphur, technicium 99m , yttrium 90 and combinations thereof.
10 . The diagnostic probe molecule according to claim 1 , wherein the label is fluorescent and selected from 7-amino-4-methylcoumarin-3-acetic acid, boron-dipyrromethene 630/650, boron-dipyrromethene 650/665, boron-dipyrromethene fluorescein analog, boron-dipyrromethene rhodamine 6G analog, boron-dipyrromethene tetramethylrhodamine analog, Cyanine 3, Cyanine 5, 6-Carboxyfluorescein, Fluorescein Isothiocyanate, Hexachloro-fluorescein, 6-Carboxy-4′,5′-dichloro-2′,7′-dimethoxyfluorescein, 2′,7′-difluorofluorescein 488, 2′,7′-difluorofluorescein 500, 2′,7′-difluorofluorescein 514, 7-Amino-4-methylcoumarin, Carboxy-X-rhodamine, Tetrachloro-fluorescein, Tetramethylrhodamine and Sulforhodamine 101 acid chloride.