Associate Professor, Cell Physiology and Molecular Biophysics

Director, Center for Membrane Protein Research

lan guan

3601 4th Street, STOP 6551
Lubbock, Texas 79430
Office Phone: (806) 743-3102
Office Room: 5A148A

Research Interest:

Membrane proteins constitute ~30% of all eukaryotic proteins and play crucial roles in many aspects of cell function. The long-term goal of our research is to understand the mechanisms of solute transport. Currently, we are studying cation-coupled bacterial and human transporters by utilizing an integrated approach including X-ray crystallography, ligand binding thermodynamics, genetic engineering, novel amphiphiles, and many other biochemical & biophysical analyses.

Research Support:

NIH (active R01 & R21) | NSF | NHARP | CH Foundation

2018 & Other Selected Publications:

  Bae, HE., Du, Y, Hariharan P, Mortensen, JS, Kumar K, Ha, B, Das, M, Lee, HS, Loland, CJ, Byrne B, Guan, L, Kobilka BK, and Chae PS. (2018) Asymmetric maltose neopentyl glycol amphiphiles for membrane protein study: Effect of detergent asymmetricity on protein stability. Chemical Science
  Hussain H, Helton T, Hariharan P, Du Y, Mortensen, JS, Ehsan M, Bernadette Byrne B, Loland CJ, Kobilka BK, Guan L, and Chae PS. (2018) A comparative study of branched and linear mannitol-based amphiphiles on membrane protein stability.  Analyst DOI: 10.1039/c8an01408f
  Hariharan, P., Tikhonova, E., Medeiros-Silva, J., Jeucken, A., Bogdanov, M.V., Dowhan, W., Brouwers, J. F., Weingarth, M. and Guan, L. (2018) Structural and functional characterization of protein–lipid interactions of the Salmonella typhimurium melibiose transporter MelB. BMC Biology 16:85 doi: 10.1186/s12915-018-0553-0
  Das, M., Du, Y., Mortensen, J.S., Hariharan, P., hsan, M., Byrne, B., Loland, C.J., Guan, L., Kobilka, B.K., and Chae, P.S. (2018) Rationally engineered tandem facial amphiphiles for improved membrane protein stabilization efficacy. ChemBioChem 19, 2225 – 2232 DOI: 10.1002/cbic.201800388
  Guan, L. (2018) Na(+)/Melibiose Membrane Transport Protein, MelB. In: Roberts G., Watts A., European Biophysical Societies (eds) Encyclopedia of Biophysics. Springer. DOI: 10.1007/978-3-642-35943-9_10082-1
  Guan, L. & Kaback, H.R. (2018) H(+)/Lactose Membrane Transport Protein, LacY. In: Roberts G., Watts A., European Biophysical Societies (eds) Encyclopedia of Biophysics. DOI: 10.1007/978-3-642-35943-9_665-1
  Ehsan, M., Das, M., Stern, V., Du, Y., Mortensen, J.S., Hariharan, P., Byrne, B., Loland, C.J., Kobilka, B.K., Guan, L., and Chae, PS. (2018) Steroid-based amphiphiles for membrane protein study: Importance of alkyl spacer for protein stability  ChemBioChem  19(13):1433-1443. DOI10.1002/cbic.201800106
  Guan, L. & Kaback, H.R. (2018) Lactose Permease: From Membrane to Molecule to Mechasnism. Handbook of Hydrocarbon and Lipid Microbiology Series. Biogenesis of Fatty Acids, Lipids and Membranes. (Springer, 2nd Edition). DOI: 10.1007/978-3-319-43676-0_48-1.
Ehsan, M., Du, Y., Molist, I., Seven, A.B., Hariharan, P., Mortensen, J.,S., Ghani, L., Loland, J.C., Skiniotis, G., Guan, L., Byrne, B., Kobilka, B., and Chae, P.S. (2018) Vitamin E-based glycoside amphiphiles for membrane protein structural studies. Organic & Biomolecular Chemistry. 16:2489-2496. DOI: 10.1039/c8ob00270c
ncbi Hariharan, P. & Guan. L. (2017) Thermodynamic cooperativity of cosubstrate binding and cation selectivity of Salmonella typhimurium MelB. J Gen Physiol. (On the Cover and Highlighted by Research News, “A symporter’s secrets shown”). DOI: 10.1085/jgp.201711922. 149(11):1029-1039. DOI: 10.1085/jgp.201711788.
ncbi Hariharan, P., Balasubramaniam, D., Peterkofsky, A., Kaback, H.R., and Guan, L. (2015) Thermodynamic mechanism for inhibition of lactose permease by the phosphotransferase protein IIAGlc. Proc Natl Acad Sci USA. 112(8):2407-2412. DOI: 10.1073/pnas.1500891112.
ncbi Tikhonova, E.B., Ethayathulla, A.S., Su, Y., Hariharan, P., Xie, S., and Guan. L. (2015) A transcription blocker isolated from a designed repeat protein combinatorial library. Scientific Reports. 5:8070. DOI: 10.1038/srep08070.
ncbi Hariharan, P. & Guan, L. (2014) Insights into the inhibitory mechanisms of the regulatory protein IIAGlc on melibiose permease activity. J. Biol. Chem. 289(47):33012-33019. DOI: 10.1074/jbc.M114.609255.
ncbi Ethayathulla, A.S., Yousef, M.S., Amin, A., Leblanc, G., Kaback, H.R., and Guan, L. (2014) Structure-based mechanism for Na(+)/melibiose symport by MelB. Nature Communications. 5: 3009. DOI:10.1038/ncomms4009.
ncbi Chae, P.S., Rasmussen S.G.F., Rana, R., Gotfryd, K., Chandra, R., Goren, M.A., Kruse, A.C., Nurva, S., Loland, J.C., Pierre, Y., Drew, D., Popot, J.L., Picot, D., Fox, B.G., Guan, L., Gether, U., Byrne, B., Kobilka, B., and Gellman, S.H. (2010) Maltose–neopentyl glycol (MNG) amphiphiles for solubilization, stabilization, and crystallization of membrane proteins. Nature Methods.  7(12):1003-1008. DOI: 10.1038/nmeth.1526.
ncbi Guan, L., Mirza, O., Verner, G., Iwata, S, and Kaback, H.R. (2007) Structural determination of the wild-type lactose permease. Proc Natl Acad Sci U S A, 104 (39):15294-15298. DOI: 10.1073/pnas.0707688104.
ncbi Guan, L. & Kaback, H.R. (2007) Site-directed alkylation of cysteine to test solvent accessibility of membrane proteins. Nature Protocols. 2(28), 2012-2017. DOI: 10.1038/nprot.2007.275.
ncbi Guan, L. & Kaback, H.R. (2006) Lessons from lactose permease. Annual Review of Biophysics & Biomolecular Structure. (35):67-91.DOI: 10.1146/annurev.biophys.35.040405.102005.
ncbi Guan, L. & Kaback, H.R. (2004) Glucose/Sugar Transport in Bacteria. Encyclopedia of Biological Chemistry. 2; 204-207 (Elsevier Inc., updated in 2013). 

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Lan Guan, M.D. Ph.D.


Update on: 08/05/2018