Cell Physiology and Molecular Biophysics
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Lan Guan, M.D., Ph.D.Assistant ProfessorCell Physiology and Molecular BiophysicsPh.D.,Tokai University School of Medicine,Isehara Japan, 2000 |
Texas Tech University Health Sciences Center
3601 4th Street, STOP 6551
Lubbock, Texas 79430
Phone: (806) 743-3102
FAX: (806) 743-1512
Email: Lan.Guan@ttuhsc.edu
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 mechanism of solute/cation symport. Currently, we are studying bacterial melibiose permease, a model system, to understand Na+/sugar cotransport using an integrated approach including X-ray crystallography, genetic engineering, and biochemical/biophysical analysis. This research is funded by The National Science Foundation and The Texas Norman Hackerman Advanced Research Program. We are also developing novel in vitro techniques for the discovery of protein-capture reagents that, like an antibody, bind to a target protein and may modulate its function. This research is funded by The National Institutions of Health.
Current Publication List
Research Articles
[30] Jakkula, S. V. and Guan, L. (2012) Reduced Na+ affinity increases turnover of MelBst. J. Bac. 51(13):2950-7. PMCID: PMC3458675
[29] Chae, P. S., Rasmussen, S. G. F., Rana, R. R., Gotfryd, K. G., Kruse, A. C., Manglik, A., Cho, K. H., Nurva, S., Gether, U., Guan, L., Loland, C. J., Byrne, B., Kobilka, B. K., and Gellman, S. H. (2012) A new class of amphiphiles bearing rigid hydrophobic groups for solubilization and stabilization of membrane proteins. Chem 18(31):9485-90. PMID:22730191
[28] Guan, L., Jakkula, S. V., Hodkoff, A. A., and Su, Y. (2012) Role of Gly117 in the cation/melibiose symport of MelB of Salmonella typhimurium. Biochemistry. 51(13):2950-7. PMCID: PMC3334291
[27] Jiang, X., Guan, L., Zhou, Y., Hong, W. X., Zhang, Q., and Kaback, H. R. (2012) Evidence for an intermediate conformational state of LacY. Proc Natl Acad Sci USA. 109(12):E698-704. PMCID: PMC3311394
[26] Zhou, Y., Madej, M. G., Guan, L., Nie, Y., and Kaback, H. R. (2011) An early event in the transport mechanism of LacY: Interaction between helices V and I. J Biol Chem. 286(35):30415-22. PMCID: PMC3162401
[25] Chaptal, V, Kwon, S, Sawaya, MR, Guan, L, Kaback, HR, and Abramson, J (2011). Crystal structure of lactose permease in complex with an affinity inactivator yields new insight into sugar recognition. Proc Natl Acad Sci U S A. 108(23):9361-6. PMID: 21593407
[24] Kudugunti, SK, Thorsheim, H, Yousef, MS, Guan, L, and Moridani, MY (2011). The metabolic bioactivation of caffeic acid phenethyl ester mediated by tyrosinase selectively inhibits glutathione S-transferase. Chem Biol Interact. 192(3):243-56. PMID: 21458432
[23] Guan, L., Nurva, S., and Ankeshwarapu, S. P. (2011) Mechanism of melibiose/cation symport of the melibiose permease of Salmonella typhimurium. J Biol Chem. 286:6367-74 PMID: 21148559
[22] 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):1003-8. PMID: 21037590
[21] Guan, L. and Kaback, H. R. (2009). Properties of a LacY efflux mutant. Biochemistry 48(39):9250-5. PMCID: PMC2754601
[20] Yousef, M. S. & Guan, L. (2009). A 3-D structure model of the melibiose permease of Escherichia coli represents a distinctive fold for Na+ symporters. Proc Natl Acad Sci U S A. 106:15291-6. PMCID: PMC2729278
[19] Zhou, Y. G., Guan, L., Freites, J. A., and Kaback, H. R. (2008). Opening and closing of the periplasmic gate in lactose permease. Proc Natl Acad Sci U S A, 105 (10):3774-3778. PMCID: PMC2268789
[18] 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):15294-8. PMCID: PMC2000551
[17] Guan, L. & Kaback, H. R. (2007). Site-directed alkylation of cysteine to test solvent accessibility of membrane proteins. Nature protocol, 2, 2012 -7. PMCID: PMC2775809
[16] Orsolya, K.*, Guan, L.*, Szepessy, E., Kukor, Z., Tóth, M., and Sahin-Tóth, M. (2006). Expression of human cationic trypsinogen with an authentic N terminus using inteinmediated splicing in aminopeptidase P (pepP) deficient Escherichia coli. Protein Expr Purif., 48(1):104-11 (*equal contribution). PMCID: PMC1604731
[15] Mirza, O.*, Guan, L.*, Verner, G., Iwata, S., and Kaback, H. R. (2006). Structural evidence for sugar recognition and mechanism for galactoside/H+ symport in the lactose permease. EMBO J, 25:1177-83 (*equal contribution). PMCID: PMC1422171
[14] Guan, L., Smirnova, I., Verner, G., Nagamoni, S., and Kaback, H. R. (2006). Manipulating phospholipids for crystallization of a membrane transport protein. Proc Natl Acad Sci U S A, 103 (6):1723-1726. PMCID: PMC1413674
[13] Guan, L. and 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):12148-52. PMCID: PMC514448
[12] Vázquez-Ibar, J. L., Guan, L., Weinglass, A. B., Verner, G., Gordillo, R., and Kaback, H. R. (2004). Sugar recognition by the lactose permease of Escherichia coli. J Biol Chem, 19;279(47):49214-21. PMID: 15364943
[11] Vázquez-Ibar, J. L.*, Guan, L.*, Svrakic, M., and Kaback, H. R. (2003). Exploiting luminescence spectroscopy to elucidate the interaction between sugar and a tryptophan residue in the lactose permease of Escherichia coli. Proc Natl Acad Sci U S A, 100 (22):12706-11 (*equal contribution). PMCID: PMC240682
[10] Ermolova, N., Guan, L., and Kaback, H. R. (2003). Intermolecular thiol cross-linking via loops in the lactose permease of Escherichia coli. Submitted to Proc Natl Acad Sci U S A, 100 (18):10187-92. PMCID: PMC193537
[9] Guan, L., Sahin-Toth, M., Kalai, T., Hideg, K., and Kaback, H. R. (2003). Probing the mechanism of a membrane transport protein with affinity inactivators. J Biol Chem, 278(12):10541-8 (cover of JBC). PMID: 12471022
[8] Guan, L., Hu, Y.L., and Kaback, H. R. (2003). Aromatic stacking in sugar binding site of lactose permease in Escherichia coli. Biochemistry, 42(6):1377-82, (accelerated publication). PMID: 12578349
[7] Sorgen, P. L., Hu, Y. L., Guan, L., Kaback, R. H., and Girvin, M. (2002). An approach to membrane protein structure without crystals. Proc Natl Acad Sci U S A, 99(22):14037-40. PMCID: PMC137832
[6] Guan, L., Sahin-Toth, M., and Kaback, H. R. (2002). Changing the lactose permease of Escherichia coli into a galactose-specific symporter. Proc Natl Acad Sci U S A, 99(10):6613-8. PMCID: PMC124451
[5] Guan, L., Murphy, F. D., and Kaback, H. R. (2002). Surface-exposed positions in the transmembrane helices of the lactose permease of Escherichia coli determined by intermolecular thiol cross-linking. Proc Natl Acad Sci U S A, 99(6):3475-80. PMCID: PMC122548
[4] Zhang, W., Guan, L., and Kaback, H. R. (2002). Helices VII and X in the lactose permease of Escherichia coli: proximity and ligand-induced distance changes. J Mol Biol, 315(1):53-62. PMID: 11771965
[3] Guan, L., Weinglass, A. B., and Kaback, H. R. (2001). Helix packing in the lactose permease of Escherichia coli: localization of helix VI. J Mol Biol, 312(1):69-77. 11545586
[2] Guan, L. and Nakae, T. (2001). Identification of essential charged residues in transmembrane segments of the multidrug transporter MexB of Pseudomonas aeruginosa. J Bacteriol, 183(5):1734-9. PMCID: PMC95059
[1] Guan, L., Ehrmann, M., Yoneyama, H., and Nakae, T. (1999). Membrane topology of the xenobiotic-exporting subunit, MexB, of the MexA,B-OprM extrusion pump in Pseudomonas aeruginosa. J Biol Chem, 4(15):10517-22. PMID: 10187844 >> Download PDF File
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Book Chapters and Reviews
[4] Kiraly, O., Guan, L., and Sahin-Toth, M. (2011) Expression of recombinant proteins with uniform N-termini. Heterologous Gen Expression in E. coli, Methods in Molecular Biology. Springer Science & Business Media, LLC. Volume 705 (Chapter 10), 175-194. PMID: 21125386
[3] Guan, L. & Kaback, H. R. (2006). Lessons from lactose permease. Annual Review of Biophysics & Biomolecular Structure (35):67-91. PMCID: PMC2802108
[2] Guan, L. & Kaback, H. R. (2004). Glucose/Sugar Transport in Bacteria. Encyclopedia of Biological Chemistry, Volume 2. p. 204-207, Elsevier Inc.
[1] Nakae, T., Guan, L., Yoneyama, H., Germ, M., and Nakajima, A. (2002). The topological localization of the subunit proteins of the three-component RND-efflux pump, MexAB-OprM in Pseudomonas aeruginosa. Proceedings of SPIE (4625):106-117.
Last revised, July 24, 2012