1Department of Physiology, Jules Stein Eye Institute and Howard Hughes Medical Institute, University of California, Los Angeles
Here we describe an optimized technique to produce high-quality vitamin A/RBP complex and two real-time monitoring techniques to study vitamin A transport by STRA6, the RBP receptor.
Published January 28, 2013. Keywords: Biochemistry, Molecular Biology, Genetics, Cellular Biology, Molecular Biology, Anatomy, Physiology, Ophthalmology, Proteomics, Proteins, Membrane Transport Proteins, Vitamin A, retinoid, RBP complex, membrane transport, membrane receptor, STRA6, retinol binding protein
1College of Nursing, Interdisciplinary Life Sciences Research Laboratory, Seattle University, 2College of Science and Engineering, Interdisciplinary Life Sciences Research Laboratory, Seattle University, 3School of Medicine, University of Washington
An in vitro method for preparing functional glucocorticoid receptor (GR)•hsp90 protein complexes from purified proteins and cellular lysates is described. The method utilizes immunoadsorption of recombinant GR followed by salt-stripping and protein complex reconstitution. The importance of cofactors and buffer conditions are discussed, as are potential method applications.
Published September 21, 2011. Keywords: Biochemistry, glucocorticoid receptor, hsp90, molecular chaperone protein, in vitro reconstitution, steroid binding, biochemistry, immunoadsorption, immunoprecipitation, Experion, western blot
1Pharmacology & Chemical Biology Department, University of Pittsburgh School of Medicine
Here we demonstrate the use of fluorescent Alexa dye coupled to α-bungarotoxin to measure GABA A receptor surface localization and endocytosis in hippocampal neurons. Through the use of constructs bearing a short extracellular tag that binds α-bungarotoxin, analysis of plasma membrane protein endocytic trafficking can be achieved.
Published March 28, 2014. Keywords: Neuroscience, α-bungarotoxin, binding site, endocytosis, immunostaining, rodent hippocampal neurons, receptor, trafficking, plasma membrane
1Center for Computational Medicine and Bioinformatics, University of Michigan, 2Center for Bioinformatics and Department of Molecular Bioscience, University of Kansas
Guidelines for computer based structural and functional characterization of protein using the I-TASSER pipeline is described. Starting from query protein sequence, 3D models are generated using multiple threading alignments and iterative structural assembly simulations. Functional inferences are thereafter drawn based on matches to proteins with known structure and functions.
Published November 3, 2011. Keywords: Biochemistry, On-line server, I-TASSER, protein structure prediction, function prediction
1Department of Chemical and Biological Engineering, Princeton University
We developed computational de novo protein design methods capable of tackling several important areas of protein design. To disseminate these methods we present Protein WISDOM, an online tool for protein design (http://www.proteinwisdom.org). Starting from a structural template, design of monomeric proteins for increased stability and complexes for increased binding affinity can be performed.
Published July 25, 2013. Keywords: Genetics, Molecular Biology, Bioengineering, Biochemistry, Biomedical Engineering, Chemical Engineering, Computational Biology, Genomics, Proteomics, Protein, Protein Binding, Computational Biology, Drug Design, optimization (mathematics), Amino Acids, Peptides, and Proteins, De novo protein and peptide design, Drug design, In silico sequence selection, Optimization, Fold specificity, Binding affinity, sequencing
1Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University
The protocols here describe kinetic assays of protein-protein interactions with Bio-layer Interferometry. F-type ATP synthase, which is involved in cellular energy metabolism, can be inhibited by its ε subunit in bacteria. We have adapted Bio-layer Interferometry to study interactions of the catalytic complex with ε’s inhibitory C-terminal domain.
Published February 18, 2014. Keywords: Chemistry, ATP synthase, Bio-Layer Interferometry, Ligand-induced conformational change, Biomolecular Interaction Analysis, Allosteric regulation, Enzyme inhibition
1Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford
Kindlins are fundamental to cell adhesion through integrins but studies of them have been hampered by the difficulty encountered in expressing them recombinantly in bacterial hosts. We describe here methods for their efficient production in baculovirus-infected insect cells.
Published March 19, 2014. Keywords: Virology, Heterologous protein expression, insect cells, Spodoptera frugiperda, baculovirus, protein purification, kindlin, cell adhesion
1Department of Biochemistry, Purdue University
Drosophila tissues often contain a heterogeneous mixture of cell types. To examine gene expression in specific cell types from a particular tissue, nuclei can be genetically tagged and subsequently isolated using an affinity-based approach. Isolated nuclei can be used for downstream applications such as gene expression analysis and chromatin immunoprecipitation.
Published March 25, 2014. Keywords: Biochemistry, Gene Expression, nuclei isolation, Drosophila, KASH, GFP, cell-type specific
1Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, 2Quantitative Biology, Eli Lilly and Company
Persistent activation of inhibitory G protein-coupled receptors results in sensitization of adenylyl cyclase signaling. To identify the essential molecular pathways, nonbiased approaches are necessary; however, this strategy requires the development of a scalable cell-based cAMP sensitization assay. Herein, we describe a sensitization assay for small molecule and siRNA screening.
Published January 27, 2014. Keywords: Bioengineering, adenylyl cyclase, cAMP, heterologous sensitization, superactivation, D2 dopamine, μ opioid, siRNA
1Laboratory of Chemical Biology and Signal Transduction, The Rockefeller University
We genetically-encode the unnatural amino acid, p-azido-L-phenylalanine at various targeted positions in GPCRs and show the versatility of the azido group in different applications. These include a targeted photocrosslinking technology to identify residues in the ligand-binding pocket of a GPCR, and site-specific bioorthogonal modification of GPCRs with a peptide-epitope tag or fluorescent probe.
Published September 13, 2013. Keywords: Genetics, Receptors, G-Protein-Coupled, Protein Engineering, Signal Transduction, Biochemistry, Unnatural amino acid, site-directed mutagenesis, G protein-coupled receptor, targeted photocrosslinking, bioorthogonal labeling, targeted epitope tagging