TTUHSC School of Medicine
HomeSchool of MedicineCell Physiology and Molecular BiophysicsFacultyLan Guan

Lan Guan, M.D., Ph.D.

Photograph of Dr. Guan

Associate Professor

     Cell Physiology and Molecular Biophysics


     Center for Membrane Protein Research

Ph.D., Tokai University School of Medicine, Japan, 2000
M.D., Chongqing Medical University, China, 1984

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

Research Interests

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/cation symport. Currently, we are studying cation-coupled bacterial and human transporters by utilizing an integrated approach including X-ray crystallography, ligand binding thermodynamics, genetic engineering, and many other biochemical & biophysical analyses.

Current Publication List

Research Articles Since 2017

  1. Hariharan, P. & Guan. L. (2017) Thermodynamic cooperativity of cosubstrate binding and cation selectivity of Salmonella   typhimurium MelB. J Gen Physiol 149(11):1029-1039. DOI: 10.1085/jgp.201711788. Complete Article.
      •  JGP   Cover of November Issue
      • Highlighted by Research News; “A symporter’s secrets shown” DOI: 10.1085/jgp.201711922. Complete Article.
  2. Sadaf, A., Du, Y., Santillan, C., Mortensen, J.S., Perez, I.M. Seven, A.B., Hariharan, P., Skiniotis, G., Loland, C.J., Kobilka, B.K., Guan, L., Byrne, B.  and Chae, P. S. (2017) Dendronictrimaltoside amphiphiles (DTMs) for membrane protein structure study.  Chem. Sci., 8 (12), 8315-8324. 10.1039/C7SC03700G
  3. Ehsan, M., Ghani, L., Du, Y., Hariharan, P., Mortensen, J.S., Ribeiro, O., Hu, H., Skiniotis, G., Loland, C.J., Guan, L., Kobilka, B.K., Byrne, B., and Chae, P.S. (2017) New penta-saccharide-bearing tripod amphiphiles for membrane protein structure studies. Analyst 142(20):3889-3898. DOI: 10.1039/c7an01168g. Complete Article.
  4. Das, M., Du, Y., Mortensen, J.S., Ribeiro, O., Hariharan, P., Guan, L., Loland, C.J., Kobilka, B.K., Byrne, B., and Chae, P.S. (2017) Butane-1,2,3,4-tetraol-based amphiphilic stereoisomers for membrane protein study: importance of chirality in the linker region. Chem Sci 8(2):1169-1177. DOI: 10.1039/c6sc02981g. Complete Article. 
  5. Hussain, H., Mortensen, J.S., Du, Y., Santellan, C., Ribeiro, O., Go, J, Hariharan, P., Loland, C.J., Guan, L., Kobilka, B.K., Byrne, B., Chae, P.S. (2017). Tandem malonate-based glucosides (TMGs) for membrane protein structural studies. Scientific Reports 7: 3963. DOI: 10.1038/s41598-017-03809-3. Complete Article.
  6. Hussain, H., Du, Y., Tikhonova, E., Mortensen, J.S., Ribeiro, O., Santellan, C., Das, M., Loland, C.J., Guan, L., Kobilka, B.K., Byrne, B., Chae, P.S. (2017). Resorcinarene-based facial glycosides: implication of detergent flexibility on membrane protein stability. Chemistry - A European Journal. 23 (28): 6724–6729. DOI: 10.1002/chem.201605016. Complete Article.
  7. Das, M., Du, Y., Ribeiro, O., Hariharan, P., Mortensen, J.S., Dhabaleswar, P., Georgios, S., Loland, C.J., Guan, L., Kobilka, B.K., Byrne, B., and Chae, P.S. (2017). Conformationally preorganized diastereomeric norbornane-based maltosides (NBMs) for membrane protein study: Implications of detergent kink for micellar properties. J. Am. Chem. Soc., 2017, 139 (8), pp 3072–3081. DOI: 10.1021/jacs.6b11997. Complete Article.

Other Selected Articles

  1. Hariharan, P., Balasubramaniam, D., Peterkofsky, A., Kaback, H.R., and Guan, L. (2015) Thermodynamic mechanism for inhibition of lactose permease by the phosphotransferase protein IIAGlcProc Natl Acad Sci USA. 112(8):2407-2412.DOI: 10.1073/pnas.1500891112. Complete Article. 
  2. 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. Complete Article.
  3. 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. Complete Article.
  4. 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 Communications5: 3009. DOI:10.1038/ncomms4009. Complete Article.
  5. Chae, P.S., Rasmussen S.G.F., Rana, R., Gotfryd, K., Chandra, R., Goren, M.A., Kruse, A.C., Nurva, S., Loland, C.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. Complete Article.
  6. 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. Complete Article.
  7. Guan, L. & Kaback, H.R. (2004) Binding affinity of lactose permease is not altered by the H+ electrochemical gradient.  Proc Natl Acad Sci U S A, 101 (33):12148-12152. DOI:10.1073/pnas.0404936101. Complete Article.

Book Chapters and Reviews

  1. Guan, L. (2017) Na+/Melibiose Membrane Transport Protein, MelB. Encyclopedia of Biophysics (Springer, in press).
  2. Guan, L. & Kaback, H.R. (2012) H+-lactose membrane transport protein, LacY. Encyclopedia of Biophysics, 936-943 (Springer, updated in 2017).
  3. 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. Complete Article.
  4. 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. Complete Article.
  5. Guan, L. & Kaback, H.R. (2004) Glucose/Sugar Transport in Bacteria. Encyclopedia of Biological Chemistry, 2; 204-207 (Elsevier Inc., updated in 2013).

A Complete List of Publications

Updated 01/16/2018