Dr. Jayasinghe joined the Chemistry & Biochemistry department in the fall of 2005 after completing postdoctoral training at the University of Southern California.  At CSUSM, Dr. Jayasinghe teaches classes in biochemistry (CHEM 341: General Biochemistry, CHEM 450: Protein Structure and Function), general chemistry (CHEM 105: General, Organic, and Biochemistry), as well as chemistry for general education (CHEM 315: Science in Film and TV).

Dr. Jayasinghe's research involves the use of biochemical and biophysical techniques to investigate the structure and membrane association of polypeptides.  At the present time, the main research projects in the laboratory involve attempts to elucidate the structure and function of several proteins (CsgA, CsgB, CsgE, CsgF, and CsgG) involved in the formation of bacterial curli.

Dr. Jayasinghe's lab page

Postdoctoral Training: 2001-2005, Department of Biochemistry and Molecular Biology, University of Southern California, Los Angeles.

Postdoctoral Training: 1999-2001, Department of Physiology and Biophysics, University of California, Irvine.

Ph.D., Chemistry: 1993-1998, Unviersity of Virginia, Charlottesville.

B.A., Chemistry: 1989-1993, Ohio Wesleyan University, Delaware, OH.

In a broad sense, my research involves the use of biochemical and biophysical techniques to investigate the structure and membrane association of polypeptides.  At the present time, my research involves three main areas of investigation:

1. Determining the structure of thin aggregative fimbriae (curli) of salmonella.
2. Investigating the sequence and structural characteristics that govern the aggregation of islet amyloid polypeptide (IAPP).
3. Determining the conformation changes associated with the structural inter-conversion and membrane association of human C-reactive protein (hCRP)

Conference Presentations by CSUSM Undergraduates

William Huegel, Amanda Green, Jessica Spolarich and Sajith Jayasinghe.  (2013).  Structural Characteris.cs of Curli Proteins AgfA, AgfF, and AgfE.  Presented at the 25th Annual CSU Biotechnology Symposium.  Aneheim, CA.

Hulya Poyrazoglu and Sajith Jayasinghe.  (2013).  Comparison of the amphipathicity and hydrophobicity of helical transmembrane segments from bacterial outer and inner membrane proteins.  Presented at the 25th Annual CSU Biotechnology Symposium.  Aneheim, CA.

Challeng Yang, Arthur Ledesma, William Huegel, and Sajith Jayasinghe. (2012).  Secondary Structure of Curli Assembly Proteins CsgE, CsgF, and CsgG.  Presented at the 24th Annual CSU Biotechnology Symposium.  San Jose, CA.

Ekta Priyam and Sajith Jayasinghe. (2012).  Sequence Based Identification of Bacterial Outer Membrane Lipoproteins with Helical Transmembrane Segments.  Presented at the 24th Annual CSU Biotechnology Symposium.  San Jose, CA.

H. Chavda and S. Jayasinghe. (2011). Determining the Energetics of rIAPP and CGRP Lipid Membrane Binding Using Circular Dichroism Spectroscopy. Presented at the 23rd Annual CSU Biotechnology Symposium, Anaheim, CA.

C. Dale, A. Fenner, W. Wong., and S. Jayasinghe. (2011). Characterizing the Aggregation of Salmonella Thin Aggregative Fimbril Protein AgfA.  Presented at the 23rd Annual CSU Biotechnology Symposium, Anaheim, CA.

M. L. Harrington, J. Oberg, S. Jayasinghe. (2009). Investigating the Membrane Interaction of Human Islet Amyloid Polypeptide at Physiological
Phosphatidylserine Concentrations. Presented at the 21th Annual CSU Biotechnology Symposium, Los Angeles, CA.

K. Wong, J. Quintero, S. Jayasinghe. (2009). Purification of Salmonella AgfA and Human C-Reactive Protein: Model Systems for Investigating Amyloid Structure. Presented at the 21st Annual CSU Biotechnology Symposium, Los Angeles, CA.

K. Bywaters, K. Wong, R. Gray, S. Jayasinghe. (2008). Is the Native Disulfide Bond Important for the Structure and Function of C-Reactive Protein? Presented at the Southern California Undergraduate Research Conference in Chemistry and Biochemistry. University of California, Riverside, CA.

A. Weber, R. Calibuyot, A. Tahami, S. Jayasinghe. (2008). Using Members of the Calcitonin Gene Related Peptide Superfamily as Model Systems for Investigating the Membrane Interaction of Human Islet Amyloid Polypeptide. Presented at the Southern California Undergraduate Research Conference in Chemistry and Biochemistry. University of California, Riverside, CA.

A. Tahami, T. McIntyre, R. Gray, S. Jayasinghe. (2007). Membrane Interaction of rat Islet Amyloid Polypeptide. Presented at the 19th Annual CSU Biotechnology Symposium, Los Angeles, CA.

K. Eusko, E. Lauri, M. Stecker, R. Gray, S. Jayasinghe. (2007). Membrane Interaction of Peptides from the Calcitonin Gene Related Peptide Superfamily. Presented at the 19th Annual CSU Biotechnology Symposium, Los Angeles, CA.

Conference Presentations

Jayasinghe, S., and Langen R., (2004). Lipid membranes modulate human islet amyloid polypeptide aggregation. Protein Science, 13.

Jayasinghe, S., Apostolidou, M., and Langen, R. (2004). Characterizing Fibrillar Human Islet Amyloid Polypeptide (IAPP). Biophysical Journal, 86.

Jayasinghe, S., Torok, M., and Langen, R. (2003). Interaction of Islet Amyloid Polypeptide with phospholipids vesicles. Biophysical Journal, 84.

Jayasinghe, S., and White, S.H. (2001). Partitioning of peptides at the bilayer interface: The role of helicity and pattern of hydrophobicity.
Biophysical Journal, 80:A2431.

Refereed Journal Articles

Ritzel, R.A., Jayasinghe, S., Hansen, J.B., Sturis, J., Langen, R., and Butler, P.C., (2010), Beta-cell selective K(ATP)-channel activation protects
beta cells and human islets from human islet amyloid polypeptide induced toxicity. Regulatory Peptides, 165(2-3): 158-162.

Bedrood, S., Jayasinghe, S., Sieburth, D., Chen, M., Erbel, S., Butler, P.C.,Langen, R., and Ritzel, R.A., (2009), Annexin A5 directly interacts with
amyloidogenic peoteins and reduces their toxicity. Biochemisty, 48(44):10568-76.

Snider, C., Jayasinghe, S.A., Hristova, K., White, S.H., (2009), Membrane Protein Explorer: A Tool for Exploring Membrane Protein Topology. Protein
Science,18(12):2624-8.

Apostolidou, M., Jayasinghe, S.A., Langen, R., (2008), Structure of helical membrane bound IAPP and its implications for membrane-mediated
misfolding. Journal of Biological Chemistry, 283(25):17205-17210.

Jayasinghe S.A. and Langen, R., (2007), Membrane interaction of islet amyloid polypeptide. Biochimica et. Biophysica Acta. 1768(8): 2002-2009.

Fernandez-Vidal, M., Jayasinghe, S., Ladokhin, A.S., White, S.H., (2007),Folding amphipathic helices into membranes: amphiphilicity trumps
hydrophobicity. Journal of Molecular Biology, 370: 459-470.

Meier, J.J., Kayed, R., Lin, C.Y., Gurlo, T., Haataja, L., Jayasinghe, S.,Langen, R., Glabe, C.C., Butler, P.C., (2006), Inhibition of hIAPP fibril
formation does not prevent beta-cell death: Evidence for distinct actions of oligomers and fibrils of hIAPP. American Journal of Physiology -
Endocrinology and Metabolism, 291(6): 1217-1324.

Jayasinghe, S.A., and Langen R., (2005). Lipid Membranes Modulate the Structure of Islet Amyloid Polypeptide. Biochemistry, 44: 12113-12119.

Jayasinghe, S.A., and Langen R., (2004). Identifying structural features of fibrillar islet amyloid polypeptide using site-directed spin labeling. Journal
of Biological Chemistry, 279:48420-48425.

Ellena, J.F., Moulthrop J., Wu, J., Rauch, M., Jayasinghe, S., Castle, J.D.,and Cafiso, D.S., (2004). Membrane position of a basic aromatic peptide
that sequesters phosphatidylinositol 4,5 bisphosphate determined by site directed spin labeling and high-resolution NMR. Biophysical Journal,
87:3221-3233.

Isas, J.M., Patel, D.R., Jao, C., Jayasinghe, S., Cartailler, J.P., Haigler,H.T., and Langen, R.(2003). Global structural changes in annexin 12- The
role of phospholipids, Ca2+, and pH. Journal of Biological Chemistry,278:30227-30234.

Jayasinghe, S., Hristova, K., and White, S.H. (2001). Transmembrane helix energetics and prediction accuracy. Journal of Molecular Biology,
312:927-934.

Jayasinghe, S., Hristova, K., and White, S.H. (2001). MPtopo: A database of membrane protein topology. Protein Science, 10:455-458.

White, S.H., Ladokhin, A.S., Jayasinghe, S., and Hristova, K. (2001). How membranes shape protein structure. Journal of Biological Chemistry,
276:32395-32398.

Ladokhin, A.S., Jayasinghe, S., and White, S.H. (2000). How to measure and analyze tryptophan fluorescence in membranes properly, and why
bother? Analytical Biochemistry, 285:235-245.

Hubbard, C., Singleton, D., Rauch, M., Jayasinghe, S., Cafiso, D., and Castle, D. (2000). The secretory carrier membrane protein family:
Structure and membrane topology. Molecular Biology of the Cell,11:2933-2947.

Jayasinghe, S., Barranger-Mathys, M., Ellena, J.F., Franklin, C., and Cafiso, D.S. (1998). Structural features that modulate the transmembrane
migration of a hydrophobic peptide in lipid vesicles. Biophysical Journal,74:3023-3030.

Franklin, J.C., Ellena, J.F., Jayasinghe, S., Kelsh, L.P., and Cafiso, D.S.(1994). The structure of micelle-associated alamethicin from 1H NMR.
Evidence for conformational heterogeneity in a voltage-gated peptide.Biochemistry, 33:4036-4035.