title: A new impedance based approach to test the activity of recombinant protein--Semaphorins as a test case.
abstract: The biological activity of a recombinant protein is routinely measured using a bioassay such as an enzyme assay. However, many proteins have no enzymatic activity and in many cases it is difficult to devise a simple and reliable approach to test their activity. Semaphorins, Ephrins, Slits, Netrins or amylin-assisted proteins have numerous activities affecting many systems and cell types in the human body. Most of them are also able to induce rapid cytoskeleton changes at least in some cell types. We assumed therefore, that such proteins might be tested based on their ability to modulate the cytoskeleton. Here we tested a number of semaphorins in an impedance based label-free platform that allows for dynamic monitoring of subtle morphological and adhesive changes. This system has proved to be a very fast, sensitive and effective way to monitor and determine the activity of such proteins. Furthermore we showed that it is possible to customize a cell-protein system by transfecting the cells with specific receptors and test the cell response following the addition of the recombinant ligand protein. Since other protein families such as Ephrins and Netrins can also influence the cytoskeleton of some cells, this approach may be applicable to a large number of proteins.
authors.affiliation: Human Embryonic Stem Cell Research Center, The Goldyne Savad Institute of Gene Therapy Hadassah University Medical Center, Jerusalem 91120, Israel.
authors.forename: Anastasya
authors.initials: A
authors.lastname: Birger
authors.affiliation: Department of Developmental Biology and Cancer Research, Institute of Medical Research Israel-Canada (IMRIC), Faculty of Medicine, The Hebrew University, P.O. Box 12272, 91120 Jerusalem, Israel.
authors.forename: Elazar
authors.initials: E
authors.lastname: Besser
authors.affiliation: Human Embryonic Stem Cell Research Center, The Goldyne Savad Institute of Gene Therapy Hadassah University Medical Center, Jerusalem 91120, Israel.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Reubinoff
authors.affiliation: Department of Developmental Biology and Cancer Research, Institute of Medical Research Israel-Canada (IMRIC), Faculty of Medicine, The Hebrew University, P.O. Box 12272, 91120 Jerusalem, Israel. Electronic address: odedb@ekmd.huji.ac.il.
authors.forename: Oded
authors.initials: O
authors.lastname: Behar
mesh_terms: D000818:Animals; D001681:Biological Assay / Q000379:methods*; D003599:Cytoskeleton; D017097:Electric Impedance; D006801:Humans; D008024:Ligands; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D039961:Semaphorins / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D014162:Transfection
chemical_list: D008024:Ligands; D009419:Nerve Tissue Proteins; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; D039961:Semaphorins