Biochemical Characterization of Anopheles gambiae SRPN6, a Malaria Parasite Invasion Marker in Mosquitoes
dc.contributor.author | An, Chunju | |
dc.contributor.author | Hiromasa, Yasuaki | |
dc.contributor.author | Zhang, Xin | |
dc.contributor.author | Lovell, Scott | |
dc.contributor.author | Zolkiewski, Michal | |
dc.contributor.author | Tomich, John M. | |
dc.contributor.author | Michel, Kristin | |
dc.date.accessioned | 2014-03-17T18:47:02Z | |
dc.date.available | 2014-03-17T18:47:02Z | |
dc.date.issued | 2012-11-09 | |
dc.identifier.citation | An C, Hiromasa Y, Zhang X, Lovell S, Zolkiewski M, et al. (2012) Biochemical Characterization of Anopheles gambiae SRPN6, a Malaria Parasite Invasion Marker in Mosquitoes. PLoS ONE 7(11): e48689. http://dx.doi.org/10.1371/journal.pone.0048689 | |
dc.identifier.uri | http://hdl.handle.net/1808/13179 | |
dc.description.abstract | Serine proteinase inhibitors of the serpin family are well known as negative regulators of hemostasis, thrombolysis and innate immune responses. Additionally, non-inhibitory serpins serve functions as chaperones, hormone transporters, or anti-angiogenic factors. In the African malaria mosquito, Anopheles gambiae s.s., at least three serpins (SRPNs) are implicated in the innate immune response against malaria parasites. Based on reverse genetic and cell biological analyses, AgSRPN6 limits parasite numbers and transmission and has been postulated to control melanization and complement function in mosquitoes. This study aimed to characterize AgSRPN6 biophysically and determine its biochemical mode of action. The structure model of AgSRPN6, as predicted by I-Tasser showed the protein in the native serpin fold, with three central β-sheets, nine surrounding α-helices, and a protruding reactive center loop. This structure is in agreement with biophysical and functional data obtained from recombinant (r) AgSRPN6, produced in Escherichia coli. The physical properties of purified rAgSRPN6 were investigated by means of analytical ultracentrifugation, circular dichroism, and differential scanning calorimetry tools. The recombinant protein exists predominantly as a monomer in solution, is composed of a mixture of α-helices and β-sheets, and has a mid-point unfolding temperature of 56°C. Recombinant AgSRPN6 strongly inhibited porcine pancreatic kallikrein and to a lesser extent bovine pancreatic trypsin in vitro. Furthermore, rAgSRPN6 formed inhibitory, SDS-stable, higher molecular weight complexes with prophenoloxidase-activating proteinase (PAP)1, PAP3, and Hemolymph protein (HP)6, which are required for melanization in the lepidopteran model organism, Manduca sexta. Taken together, our results strongly suggest that AgSRPN6 takes on a native serpin fold and is an inhibitor of trypsin-like serine proteinases. | |
dc.description.sponsorship | This work was supported by the National Institutes of Health through 3P20RR017708-07S1 and P20RR017686 sub-awards and 1R01AI095842 to K.M. This is contribution 12-098-J from the Kansas Agricultural Experiment Station. | |
dc.publisher | Public Library of Science | |
dc.rights | ©2012 An 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. | |
dc.rights.uri | http://creativecommons.org/licenses/by/4.0/ | |
dc.subject | Immune serum | |
dc.subject | Malaria | |
dc.subject | Malarial parasites | |
dc.subject | Mosquitoes | |
dc.subject | Proteases | |
dc.subject | Protein structure | |
dc.subject | Recombinant proteins | |
dc.subject | Serine | |
dc.title | Biochemical Characterization of Anopheles gambiae SRPN6, a Malaria Parasite Invasion Marker in Mosquitoes | |
dc.type | Article | |
kusw.kuauthor | Lovell, Scott | |
kusw.kudepartment | Higuchi Biosciences Center | |
kusw.oastatus | fullparticipation | |
dc.identifier.doi | 10.1371/journal.pone.0048689 | |
kusw.oaversion | Scholarly/refereed, publisher version | |
kusw.oapolicy | This item meets KU Open Access policy criteria. | |
dc.rights.accessrights | openAccess |
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Except where otherwise noted, this item's license is described as: ©2012 An 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.