Publications
1. Li S., Combs J. D., Alharbi O. A., Kong J., Wang C., Leblanc R. M. Chemical Communications, 2015, 51, 12537-12539. "The 13C amide I band is still sensitive to conformation change when the regular amide I band cannot be distinguished at the typical position in H2O"
2. Li S., Potana S., Keith D. J., Wang C., Leblanc R. M. Chemical Communications, 2014, 50, 3931-3933. "Isotope-edited FTIR in H2O: Determination of the conformation of specific residues in a model α-helix peptide by 13C labeled carbonyls"
3. Xu J., Wang C., Wang J., Huo Q., Crawford N. F., Veliz E. A., Leblanc R. M., Journal of Colloids and Interface Science, 2013, 393, 21-28. "Smooth surface roughness of silanized CdSe(ZnS) quantum dots"
4. Zhou B., Hao Y., Wang C., Li D., Liu Y., Zhou F. Journal of Inorganic Biochemistry, 2013, 118, 68-73. "Conversion of natively unstructured α-synuclein to its α-helical conformation significantly attenuates production of reactive oxygen species"
5. Wang Q., Shah N., Zhao C., Wang C., Zhao J., Zhou F., Zheng J. Physical Chemistry Chemical Physics, Phys.Chem.Chem.Phys, 2011, 33, 15200-15210. "Structural, morphological, and kinetic studies of β-amyloid peptide aggregation on self-assembled monolayers"
6. Wang C., Shah N., Leblanc R. M., Zhou F. Chemical Communications, 2010, 46, 6702-6704. "α-synuclein in α-helix conformation at air-water interface: implication of α-synuclein conformation, orientation, and accumulation around the vesicles in presynaptic terminals of neuronal cells"
7. Wang C., Zhang L., Liu L., Peng Y., Zhou F. Biochemistry, 2010, 49, 8134-8142. "Redox reactions and cytotoxicity of the copper complex of α-synuclein"
8. Peng Y.*; Wang C.*; Xu H.; Liu Y.; Zhou F. Journal of Inorganic Biochemistry, 2010, 104, 365-370. "Binding of α-synuclein with Fe3+ and Fe2+ and biological implications of the resultant complexes" (* contributes equally to the paper)
9. Xu J.; Wang C.; Leblanc R. M. Colloids and Surfaces B 2009, 70, 163-168. "Surface chemistry and photophysical properties of a diacetylene-peptide derivative capped quantum dots Langmuir monolayer"
10. Thakur G.; Wang C.; Leblanc R. M. Langmuir, 2008, 24, 4888-4893."Surface chemistry and in situ spectroscopy of lysozyme Langmuir monolayer"
11. Wang C.; Zheng J.; Zhao L.; Rastogi, V. K.; Shah S. S.; DeFrank J. J.; Leblanc R. M. Journal of Physical Chemistry B, 2008, 112, 5250-5256."Infrared Reflection-Absorption Spectroscopy (IRRAS) and Polarization Modulated-IRRAS (PM-IRRAS) Studies of Organophosphorus Acid Anhydrolase Langmuir Monolayer"
12. Wang C.; Micic M.; Ensor M.; Daunert S.; Leblanc R. M. Journal of Physical Chemistry B 2008, 112, 4146-4151. "Infrared Reflection-Absorption Spectroscopy (IRRAS) and Polarization Modulated-IRRAS (PM-IRRAS) Study of the Aequorin Langmuir Monolayer"
13. Wang C.; Zheng J.; Oliveira O. J.; Leblanc R. M. Journal of Physical Chemistry C 2007, 111, 7826-7833. "Nature of the interaction between a peptidolipid Langmuir monolayer and paraoxon in the subphase"
14. Wang C.; Micic M.; Ensor M.; Daunert S.; Leblanc R. M. Langmuir 2007, 23, 7602-7607. "Surface properties of 'Jellyfish': Langmuir monolayer and Langmuir-Blodgett film studies of recombinant aequorin"
15. Wang C.; Li C.; Ji X.; Orbulescu J.; Xu J.; Leblanc R. M. Langmuir 2006, 22, 2200-2204. "Peptidolipid as binding site of acetylcholinesterase: Molecular recognition of paraoxon in Langmuir films"
16. Xu J.; Ji X.; Gattas-Asfura K. M.; Wang C.; Leblanc R. M. Colloids and Surfaces A 2006, 284, S1, 35-42. "Langmuir and Langmuir-Blodgett films of quantum dots"
17. Xu J.; Li C.; Wang C.; Wang J.; Huo Q.; Leblanc R. M. Langmuir 2006, 22, 181-186. "Polymerization of a cysteinyl peptidolipid Langmuir film"
18. Ji X.; Wang C.; Xu J.; Zheng J.; Gattas-Asfura K.; Leblanc R. M. Langmuir 2005, 21, 5377-5382. "Surface chemistry studies of (CdSe)ZnS quantum dots at the air-water interface"
19. Wang Y.; Wang C.; Wang X.; Guo Y.; Xie B.; Cui Z.; Liu L.; Xu L.; Zhang D.; Yang B. Chemistry of Materials 2005, 17, 1265-1268. "Hydrogen-bonding fabrication of NLO Langmuir-Blodgett films with nontraditional molecular architecture and unique thermal stability"
20. Guo Y.; Wang Y.; Yang Q.; Li G.; Wang C.; Cui Z.; Chen J. Solid State Science 2004, 6 1001-1006. "Preparation and characterization of magadiite grafted with an azobenzene derivative"
21. Hou X.; Wu L.; Pu W.; Qin L.; Wang,C.; Zhang X.; Shen J. Colloids and Surfaces A, 2002, 198-200, 135-140. "Self-assembly and Langmuir-Blodgett (LB) film of a novel hydrogen-bonded complex: a surface enhanced Raman scattering (SERS) study"

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Parkinson's disease (PD) is characterized by the abnormal intracellular inclusions, namely, Lewy bodies, which is composed of lipids and α-synulcien (α-syn). α-Syn, a protein with 140 amino acids, is unstructured in aqueous solution and in vitro can form fibrils in β-sheet conformation which is identical to that detected in Lewy bodies. α-Syn is a 140-amino-acid presynaptic protein (shown in Scheme 1) and the sequence can be divided into three regions, namely, the positively charged N-terminus (residues 1-60), the aggregation-prone nonamyloid components (NAC, residues 60-95), and the negatively charged C-terminus (residues 95-140). My research interests focus on the biophysical characters of α-syn as summarized below.

MDVFMKGLSK AKEGVVAAAE KTKQGVAEAA GKTKEGVLYV GSKTKEGVVH
GVATVAEKTK EQVTNVGGAV VTGVTAVAQK TVEGAGSIAA ATGFV KKDQL
GKNEEGAPQE GILEDMPVDP DNEAYEMPSE EGYQDYEPEA

Scheme 1. The sequence of α-synuclein with the N-terminus underlined and the C-terminus expressed in Italics.

1. Clarify the structure of α-syn aggregates in residue level.
   Clarification of protein structure is important to address both the function of protein and the mechanism how protein works in vivo. Although X-ray crystallography is a powerful technique to elucidate the protein structure in atomic level, this technique is still limited because a large number of proteins cannot form single crystal structure. α-Syn is one of the non-crystal proteins and the structure of α-syn aggregates has been indicated to be difficult to elucidated by X-ray crystallography. Since the structure of α-syn aggregates is important for both PD pathology and drug development, a methodology which can resolve the structure will be welcome.
   
   Recently, residue-level peptide/protein structure has been elucidated by the detection of amide I band (between 1700 to 1590 cm ^-1) in infrared (IR) spectroscopy when the peptide/protein is C13 labeled. For example, the regular amide I band appears at 1620 cm 1 in β-sheet conformation because of the hydrogen bond formation between the amide groups in neighboring strands. Whereas the C13 labeled residue will show the amide I band at 1600 cm-1 when forming H-bond with regular C12 residues in the neighboring peptide chain. As the NAC part of α-syn has been shown to be responsible for the aggregation, my first project will focus on synthesize C13 labeled segment peptides of α-syn and clarify the structure of α-syn aggregates.
2. Study the lipid interaction with α-syn at the air-water interface.
   Although the aggregation of unstructured α-syn has been well studied, α-syn accumulates in the presynaptic terminals where exists high density of vesicles. α-Syn changes its conformation to α-helix in the presence of vesicles and we found that this conformation change is irreversible. Thus, the accumulation of α-syn may be due to the vesicles in presynaptic terminals and the accumulated α-syn may be extensively in α-helix in vivo. Although the aggregation of α-syn in the presence of vesicles has attracted scientific interest, controversy results have been reported possibly because the nature of α-syn interaction with phospholipids is difficult to be addressed by vesicle system.
   
   g - Research Interests The difficulty is due to the instinct isotropic character of vesicle. For instance, the orientation of alkyl chains in vesicles is distributed evenly in all directions due to the spherical shape of vesicles. Therefore, the orientation change of alkyl chains in the absence and presence of α-syn is difficult to be detected. Similarly, although α-syn has been reported to orient parallel to the vesicles surface, the sphere surface of vesicle may make the orientation of α-syn randomly distributed. Consequently, the orientation change of α-syn in the presence of phospholipids with various headgroups and alkyl chains is also difficult to compare. Thus, an anisotropic system which can also mimic membrane structure in vivo may help to clarify the nature of α-syn interaction with phospholipids and evaluate the interaction effect on the aggregation of α-syn.
   
   Langmuir monolayer technique can build up a phospholipid monolayer identical to half of cell membrane and consequently, has been widely used as model to study biophysical characters of cell membrane (shown in Scheme 2). Different to vesicles system, Langmuir monolayer is very sensitive about the molecular interaction between neighboring lipids or between lipids molecule with other molecules (e.g., proteins/peptides) in the water phase by measuring the surface pressure-area (π-A) isotherm. Furthermore, the Langmuir monolayer is anisotropic and the recently developed Infrared Reflection-Absorption Spectroscopy (IRRAS) has been proved to be a powerful technique to detect the order and orientation of the alkyl chains of phospholipids as well as the orientation change of proteins in the subphase without additional probes. My second research interest focuses on the employment of Langmuir monolayer and IRRAS techniques to study the nature of the α-syn interaction with phospholipids. As to our knowledge, no paper has been published to clarify either the α-syn interaction with phospholipids by Langmuir monolayer technique or the interaction effect on α-syn aggregation.

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