Current research in the Knight laboratory focuses on molecular interactions of proteins and lipid membranes, and on the development of single-molecule techniques for measuring them. Membrane-targeting proteins are normally soluble in the cytoplasm, but are recruited to membrane surfaces during cell signaling events. These proteins typically dock to the lipid membrane through one or more different types of molecular interactions, including (1) specific recognition of lipid headgroups as ligands; (2) nonspecific electrostatic interaction of positively charged regions of the protein with negatively charged lipids; (3) insertion of nonpolar amino acid sidechains into the hydrophobic interior of the membrane; and/or (4) interaction with other proteins on the membrane surface. We are particularly interested in discovering the molecular mechanisms of membrane interaction for proteins involved in insulin secretion. These interactions are expected to reveal important features of the proteins and membranes that enable proper regulation of secretion, and may offer clues to how secretion is dysregulated during progression of type II diabetes.

Biochemical and biophysical techniques are being used to investigate a number of individual membrane-targeting protein domains. These include a protein-to-membrane fluorescence resonance energy transfer method that can be used to measure both equilibria and kinetics of membrane binding. In addition, Dr. Knight’s recent and ongoing research has developed new applications of single-molecule fluorescence microscopy for measuring the kinetics and stoichiometry of protein-membrane binding.

Dr. Knight was introduced to the field of biophysical chemistry as an undergraduate chemistry major in the lab of Dorothy Erie. His undergraduate research involved RNA polymerases from thermophilic bacteria. Ph.D. research was completed in the lab of Prof. Andrew Miranker and focused on membrane interactions and amyloid aggregation of islet amyloid polypeptide (IAPP), a peptide secreted with insulin that forms insoluble aggregates in the diabetic pancreas. Dr. Knight continued to pursue interests in protein-membrane interaction through postdoctoral research in the laboratory of Prof. Joseph Falke at the University of Colorado at Boulder. There, his research developed methods using total internal reflection fluorescence microscopy to study these interactions at the single-molecule level.

Ph.D., Pharmacology, Yale University, 2006
B.S., Chemistry, University of North Carolina, 2000

Refereed research articles (supervised students italicized)

Chon, N.L., Tran, S., Miller, C.S., Lin, H., and Knight, J.D. (2023) A Conserved Electrostatic Membrane-Binding Surface in Synaptotagmin-Like Proteins Revealed Using Molecular Phylogenetic Analysis and Homology Modeling. BioRxIV: https://www.biorxiv.org/content/10.1101/2023.07.13.548768v1

Anantharam, A., and Knight, J.D., eds. (2022) Exocytosis: From Molecules to Cells. London: Biophysical Society/IOP Press. https://iopscience.iop.org/book/edit/978-0-7503-3771-7

Knight, J.D., Budd, S., Bruehl, M., and Pan, D. (2021) A Paired Set of Biochemistry Writing Assignments Combining Core Threshold Concepts, Information Literacy, and Real-World Applications. J Chem Educ 98, 3758-3766. https://doi.org/10.1021/acs.jchemed.1c00115  

Pan, D., Budd, S., Bruehl, M., and Knight, J.D. (2021) Tracking Information Literacy in Science Students: A Longitudinal Case Study of Skill Retention from General Chemistry to Biochemistry. J Chem Educ 98, 3749-3757. https://doi.org/10.1021/acs.jchemed.1c00114

Knight, J.D., Shearn, C.T., and Beauchamp-Pérez, C. (2021) A surprising modification lowers the lipid binding affinity of a membrane trafficking protein. ASBMB Today. https://www.asbmb.org/asbmb-today/science/082421/a-surprising-modification-lowers-the-lipid

Alnaas, A.A., Watson-Siriboe, A., Tran, S., Negussie, M., Henderson, J.A., Osterberg, J.R., Chon, N.L., Harrott, B.M., Oviedo, J., Lyakhova, T., Michel, C., Reisdorph, N., Reisdorph, R., Shearn, C.T., Lin, H., and Knight, J.D. (2021) Multivalent lipid targeting by the calcium-independent C2A domain of synaptotagmin-like protein 4/granuphilin. J Biol Chem 296, 100159. https://doi.org/10.1074/jbc.RA120.014618

Tran, H.T., Anderson, L.A., and Knight, J.D. (2019) Membrane Binding Cooperativity and Co-insertion by C2AB Tandem Domains of Synaptotagmins 1 and 7.  Biophysical Journal 116, 1025-1036.  doi: 10.1016/j.bpj.2019.01.035

MacDougall, D.D., Lin, Z., Chon, N.L., Jackman S., Lin, H., Knight, J.D., and Anantharam, A.  (2018) The high-affinity calcium sensor synaptotagmin-7 serves multiple roles in regulated exocytosis.  J. Gen. Physiol. 150 (6), 783-807.  http://jgp.rupress.org/content/150/6/783

Schenk, N.A., Dahl, P.J., Hanna, M.G., Audhya, A., Tall, G.G., Knight, J.D., and Anantharam, A. (2018) A simple supported tubulated bilayer system for evaluating protein-mediated membrane remodeling. Chemistry and Physics of Lipids 215, 18-28.  doi: 10.1016/j.chemphyslip.2018.06.002

Biochemistry (CHEM 3810)
General Biochemistry I (CHEM 4810)
General Biochemistry II (CHEM 4820)
Biochemistry Laboratory (CHEM 4828)
Graduate Biochemistry II (CHEM 5830)
Biochemistry of Metabolic Disease (CHEM/BIOL 4825/5825)
Physical Biochemistry Laboratory (CHEM 4548)