1vyf: Difference between revisions
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SCHISTOSOMA MANSONI FATTY ACID BINDING PROTEIN IN COMPLEX WITH OLEIC ACID
OverviewOverview
Schistosoma mansoni fatty acid binding protein (Sm14) was crystallized, with bound oleic acid (OLA) and arachidonic acid (ACD), and their, structures were solved at 1.85 and 2.4 A resolution, respectively. Sm14 is, a vaccine target for schistosomiasis, the second most prevalent parasitic, disease in humans. The parasite is unable to synthesize fatty acids, depending on the host for these nutrients. Moreover, arachidonic acid, (ACD) is required to synthesize prostaglandins employed by schistosomes to, evade the host's immune defenses. In the complex, the hydrocarbon tail of, bound OLA assumes two conformations, whereas ACD adopts a unique, hairpin-looped structure. ACD establishes more specific interactions with, the protein, among which the most important is a pi-cation bond between, Arg78 and the double bond at C8. Comparison with homologous fatty acid, binding proteins suggests that the binding site of Sm14 is optimized to, fit ACD. To test the functional implications of our structural data, the, affinity of Sm14 for 1,8-anilinonaphthalenesulfonic acid (ANS) has been, measured; moreover the binding constants of six different fatty acids were, determined from their ability to displace ANS. OLA and ACD exhibited the, highest affinities. To determine the rates of fatty acid binding and, dissociation we carried out stopped flow kinetic experiments monitoring, displacement by (and of) ANS. The binding rate constant of ligands is, controlled by a slow pH dependent conformational change, which we propose, to have physiological relevance.
About this StructureAbout this Structure
1VYF is a Single protein structure of sequence from Schistosoma mansoni with OLA as ligand. Structure known Active Site: AC1. Full crystallographic information is available from OCA.
ReferenceReference
Schistosoma mansoni fatty acid binding protein: specificity and functional control as revealed by crystallographic structure., Angelucci F, Johnson KA, Baiocco P, Miele AE, Brunori M, Valle C, Vigorosi F, Troiani AR, Liberti P, Cioli D, Klinkert MQ, Bellelli A, Biochemistry. 2004 Oct 19;43(41):13000-11. PMID:15476393
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