DNA encoding a His-tagged 11S globulin from Amaranthus hypochondriacus (amarantin) was successfully expressed in Escherichia coli strains BL21 (DE3) and Origami (DE3). The two strains produced different accumulation patterns. Whereas most of the proamarantin expressed in BL21 (DE3) was localized in inclusion bodies, that produced in Origami (DE3) was soluble (76 mg/L). Sucrose density gradient ultracentrifugation analysis of the expressed soluble proamarantin revealed that the protein was assembled into trimers. Treatment of proamarantin trimers in vitro using purified asparaginyl endopeptidase resulted in the appearance of peptides of the sizes expected for acidic and basic chains. Because the proamarantin assembles into trimers with the expected sedimentation characteristics and is cleaved into acidic and basic chains rather than being degraded, the results suggest that the protein folding occurring in E. coli is similar to that taking place in seeds. The His-tagged proamarantin was purified in a single step by immobilized metal affinity chromatography with a final yield of 48 mg/L. The overexpression of proamarantin in E. coli, together with the one-step purification will facilitate further investigation of this storage protein through site-directed mutagenesis.
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http://dx.doi.org/10.1021/bp049923e | DOI Listing |
BMC Musculoskelet Disord
December 2014
Department of Rheumatology and Clinical Immunology and Autoinflammatory Reference Centre at Charité, Charité-Universitätsmedizin Berlin, Charitéplatz 1, D-10117 Berlin, Germany.
Background: PA28γ (also known as Ki, REG gamma, PMSE3), a member of the ubiquitin-and ATP-independent proteasome activator family 11S, has been proved to show proteasome-dependent and -independent effects on several proteins including tumor suppressor p53, cyclin-dependent kinase inhibitor p21 and steroid receptor co-activator 3 (SCR-3). Interestingly, PA28γ is overexpressed in pathological tissue of various cancers affecting e. g.
View Article and Find Full Text PDFJ Biol Chem
January 2012
Institut für Pharmazeutische Biologie und Biotechnologie, Philipps-Universität Marburg, Deutschhausstrasse 17A, 35037 Marburg, Germany.
The putative prenyltransferase gene ACLA_031240 belonging to the dimethylallyltryptophan synthase superfamily was identified in the genome sequence of Aspergillus clavatus and overexpressed in Escherichia coli. The soluble His-tagged protein EAW08391 was purified to near homogeneity and used for biochemical investigation with diverse aromatic substrates in the presence of different prenyl diphosphates. It has shown that in the presence of dimethylallyl diphosphate (DMAPP), the recombinant enzyme accepted very well simple indole derivatives with L-tryptophan as the best substrate.
View Article and Find Full Text PDFBiotechnol Prog
April 2005
Departamento de Biotecnología y Bioquímica, Centro de Investigación y de Estudios Avanzados del IPN, Unidad Irapuato, Apartado Postal 629, Irapuato, Gto. 36500, México.
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