Heparin Clearance by Liver Scavenger Receptors
Edward N. Harris*
Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0664, US
- *Corresponding Author:
- Edward N. Harris
Department of Biochemistry
University of Nebraska-Lincoln
Lincoln, Nebraska 68588-0664, US
E-mail: [email protected]
Received Date: August 23, 2012; Accepted Date: August 23, 2012; Published Date: August 27, 2012
Citation: Harris EN (2012) Heparin Clearance by Liver Scavenger Receptors. Biochem Anal Biochem 1:e114. doi:10.4172/2161-1009.1000e114
Copyright: © 2012 Harris EN, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
The range of assay technologies for the binding and signaling has been developed in HTS laboratories for the identification of hit or lead compounds acting on GPCRs. The [35S] GTPγS binding assay still remains to be a useful and simple technique to demonstrate receptor activation and is one of the few functional, cell-free assays. However, its radioactive nature imposes clear limitations to its use in regular laboratory practice and in high-throughput experimentations. Herein, we have developed a new non-radioactive version of the assay using europium-labeled GTP analogue in which europium-GTP binding can be assayed using time-resolved fluorescence. In continuation with our efforts, this assay was adapted for Histamine 3 receptors. The assay format was specifically evaluated by testing known histamine 3 agonists (Imetit, Immepip, Methylhistamine, Proxifan and Histamine) and antagonists (GSK189254, Clobenpropit and Thioperamide) drugs. Under optimized assay conditions, the potencies (pEC50 & PKB) in the binding assay are in good agreement with those obtained previously in the isotopic functional activity assay. The Eu-GTP binding assay was observed to be highly robust (Z’ factor 0.84) with high percentage over basal counts. This assay can be utilized as a component of screening cascade for the screening of Histamine 3 receptor antagonists.