<> "The repository administrator has not yet configured an RDF license."^^ . <> . . "The P. vivax merozoite surface protein 1 (MSP-1):\r\nDevelopment of a recombinant protein production process\r\nand structural characterisation of MSP-1"^^ . "Malaria in humans is most often caused by either Plasmodium falciparum or P. vivax. Research efforts\r\nhave mostly focused on P. falciparum, despite P. vivax being the most widespread Plasmodium species.\r\nThis parasite species differs from P. falciparum in some key aspects like its ability to form dormant liver\r\nforms, an early appearance of gametocytes in the blood stream and its strict tropism to reticulocytes.\r\nAlthough P. vivax and P. falciparum invade different developmental stages of red blood cells, both express\r\na highly abundant protein on the surface of their merozoites, the merozoite surface protein 1 (MSP-1).\r\nInitially expressed as a precursor protein, MSP-1 undergoes proteolytic processing and is cleaved into four\r\nprocessing fragments called p83, p30, p38 and p42. These fragments remain non-covalently associated\r\nand are attached to the surface of the merozoite via a GPI anchor at the C-terminal fragment p42. MSP-1\r\nis considered a promising vaccine candidate and P. falciparum MSP-1D is currently tested as a vaccine in\r\na clinical trial. However, no similar vaccine was developed for P. vivax yet.\r\nThe establishment of a protein production process for P. vivax MSP-1 (PvMSP-1) was an essential part\r\nof this study. Two different methods were developed, which both use individually expressed fusion\r\nproteins to assemble the full length MSP-1 protein. One fusion protein consists of the fragments p83 and\r\np30, the other includes p38 and p42. In the first approach, the two halves are refolded together and\r\npurified by ion exchange chromatography and size exclusion chromatography. This protocol was also\r\napplied to produce P. berghei MSP-1 and test whether the assembly of a hybrid protein consisting of one\r\nP. falciparum half and one P. vivax half is possible. In the second approach contaminants are first\r\nremoved from the individual fusion proteins by high resolution ion exchange chromatography before\r\nreconstitution of MSP-1. Both techniques result in a pure MSP-1 preparation, but the second approach\r\nresults in a higher yield.\r\nThe produced recombinant proteins were structurally characterised using a combination of\r\nbioinformatical, biophysical and biochemical methods. All recombinant proteins were cleaved by\r\nP. falciparum SUB1, indicating a high conservatism of the cleavage motifs. CD spectroscopy showed a\r\nmostly alpha-helical structure and only partial unfolding of the protein at high temperatures. Interestingly,\r\nthis unfolding increased when MSP-1D was processed by SUB1 before performing thermal denaturation.\r\nThis suggests an increased stability of the MSP-1 heterodimer compared to the complex consisting of four\r\nprocessing fragments. Prediction of the secondary structure revealed unstructured regions in all analysed\r\nMSP-1 proteins. The function of these regions remains unknown, but these sites could be responsible for\r\ninteractions with other proteins. Cross-linking of MSP-1 paired with mass spectrometry uncovered a\r\npreviously unknown interaction between the p83 and p42 processing fragment, leading to an updated\r\nmodel of MSP-1 with a globular instead of asymmetrical shape.\r\nThis project provides two production processes for recombinant P. vivax MSP-1, which is now available\r\nfor further immunological studies. The structural information acquired with this and other MSP-1\r\nproteins can be used as a base to further elucidate its function and three-dimensional structure."^^ . "2018" . . . . . . . "Tanja"^^ . "Marzluf"^^ . "Tanja Marzluf"^^ . . . . . . "The P. vivax merozoite surface protein 1 (MSP-1):\r\nDevelopment of a recombinant protein production process\r\nand structural characterisation of MSP-1 (PDF)"^^ . . . "Thesis_final.pdf"^^ . . . "The P. vivax merozoite surface protein 1 (MSP-1):\r\nDevelopment of a recombinant protein production process\r\nand structural characterisation of MSP-1 (Other)"^^ . . . . . . "indexcodes.txt"^^ . . "HTML Summary of #25663 \n\nThe P. vivax merozoite surface protein 1 (MSP-1): \nDevelopment of a recombinant protein production process \nand structural characterisation of MSP-1\n\n" . "text/html" . . . "570 Biowissenschaften, Biologie"@de . "570 Life sciences"@en . .