Lan Guan, M.D. Ph.D.

Professor and Interim Chair | Cell Physiology and Molecular Biophysics

Director | Center for Membrane Protein Research

 

3601 4th Street, STOP 6551
Lubbock, Texas 79430
Office Phone: (806) 743-3102
Office Room: 5A149
E-mail: Lan.Guan@ttuhsc.edu

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 an integrated approach including X-ray crystallography, cryo-EM, ligand binding thermodynamics, genetic engineering, novel amphiphiles, and many other biochemical & biophysical analyses.

Current Support:

NIH Awards R01 & R21

Open position for PHD student

Guest Edited Collection - Scientific Reports

"Structure and mechanism of membrane transporters"

Submissions are still welcome on a rolling basis

https://www.nature.com/srep/guestedited#membrane-transporters

2021 & Other Selected Articles:

	Ehsan M., Wang,H., Cecchetti, C., Mortensen, J. S., Du, Y., Hariharan,P., Lee, H. J., Ghani, L., Guan, L., Loland, L. J., Byrne, B., Kobilka, B. K., and Chae, P. S. (2021) Maltose-bis(hydroxymethyl)phenol (MBPs) and Maltose-tris(hydroxymethyl)phenol (MTPs) Amphiphiles for Membrane Protein Stability. ACS Chemical Biology (Accepted).
	Markham, K. J., Tikhonova, E. B., Scarpa, A. C., Hariharan, P., Katsube, S, and Guan, L. (2021) Complete cysteine-scanning mutagenesis of the Salmonella typhimurium melibiose permease. J Biol Chem (Accepted).
	Guan, L., Hariharan, P. (2021) X-ray crystallography reveals molecular recognition mechanism for sugar binding in a melibiose transporter MelB. Commun Biol 4, 931. https://doi.org/10.1038/s42003-021-02462-x
	Hariharan, P. and Guan, L. (2021) Cooperative binding ensures the obligatory melibiose/Na+ cotransport in MelB. J Gen Physiol 153, e202012710. DOI: 10.1085/jgp.202012710
	Sadaf, A., Kim, S., Bae, H. E., Wang, H., Nygaard, A., Uegaki, Y., Du, Y., Munk, C. F., Katsube, S., Bae, J., Choi, C. W., Choi, H., Byrne, B., Gellman, S. H., Guan, L., Loland, C. J., Kobilka, B. K., Im, W., and Chae, P.S. (2021) Conformationally flexible core-bearing detergents with a hydrophobic or hydrophilic pendant: Effect of pendant polarity on detergent conformation and membrane protein stability. Acta Biomaterialia 128, 393-407 DOI: 10.1016/j.actbio.2021.04.043
Selected Publications in the Past Years
	Guan, L. and Hariharan, P. (2020) Molecular recognition of sugar binding in a melibiose transporter MelB by X-ray crystallography. BioRxiv Preprint. doi: https://doi.org/10.1101/2020.12.20.423627
	Guan, L. (2020) Glucose/Sugar Transport in Bacteria. Encyclopedia of Biochemistry, 3rd edition, Elsevier Inc. Published in the Life Sciences Reference Collection https://www.sciencedirect.com/science/article/pii/B9780128194607000931
	H. Ronald Kaback and Lan Guan. (2019)  It takes two to tango: the dance of the permease. J Gen Physiol. 151(7):878-886. doi: 10.1085/jgp.201912377.
	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
	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
	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.
	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.
	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.
	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.
	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.
	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.
	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.
	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.
	Guan, L. & Kaback, H.R. (2004) Glucose/Sugar Transport in Bacteria. Encyclopedia of Biological Chemistry. 2; 204-207 (Elsevier Inc., updated in 2013).