Dr. Thelma Abeysinghe

B.Sc (Kelaniya); M.Sc (Colombo); Ph.D (Iowa)

Senior Lecturer (G I)

Department of Chemistry

Dr. Thelma Abeysinghe is a  graduate from the University of Kelaniya with a B.Sc. Special Degree in Chemistry (Second Class (Honors) Upper Division). She  graduated with an M.Sc in Analytical Chemistry from the University of Colombo and holds a PhD in Chemistry from the University of Iowa, USA. Her research areas include Engineering immobilized DNAzyme sensors, pesticide absorption by plants and Food Chemistry.

Dr. Thelma is a member of many associations including, American Chemical Society,  Sri Lanka Association for the Advancement of Science (SLAAS), Sri Lanka, Institute of Chemistry Ceylon, College of Biochemists, Sri Lanka and the Organization for Women in Science for the Developing World (OWSD).

 

Biochemistry and Molecular Biology, Organic Chemistry

Pesticide Absorption by Plants, Food Chemistry
  • Senior Lecturer (Grade I) in Chemistry

2021-present, The Open university of Sri Lanka, Nawala, Nugegoda

  •  Senior Lecturer (Grade II) in Chemistry

2015-present, The Open university of Sri Lanka, Nawala, Nugegoda

  • Graduate Research Assistant

2009- 2014, Department of Chemistry, The University of Iowa, Iowa, USA

  • Research Fellow (Graduate College of Summer Fellowship)

Summer 2013, Department of Chemistry, The University of Iowa, Iowa City, IA

 

Co-ordinator for CYU5303 Organic Chemistry (B.Sc. General Degree)
Co-ordinator for CYU5306 Biochemistry (B.Sc. General Degree)
Co-ordinator for CYU6608 Research Project in Chemistry (B.Sc. Special Degree)

Engineering immobilized DNAzyme fluorescence sensors for on-site environmental monitoring of water bodies for metal contamination



DT Abeysinghe, KAH Kumara, KAD Kaushalya, UG Chandrika, D Alwis. 2021. Phytochemical screening, total polyphenol, flavonoid content, in vitro antioxidant and antibacterial activities of Sri Lankan varieties of Murraya koenigii and Micromelum minutum, Heliyon 7 (7), e07449

DT Abeysinghe, D Alwis, KAH Kumara, UG Chandrika. 2021. Nutritive Importance and Therapeutics Uses of Three Different Varieties (Murraya koenigii, Micromelum minutum, and Clausena indica) of Curry Leaves: An Updated Review. Evidence-Based Complementary and Alternative Medicine 2021. https://doi.org/10.1155/2021/5523252

IBK Thomas, KAP Gaminda, CD Jayasinghe,DT Abeysinghe, and R. Senthilnithy. DNAzymes, Novel Therapeutic Agents in Cancer Therapy: A Review of Concepts to Applications. Journal of Nucleic Acids 2021 https://doi.org/10.1155/2021/9365

Abeysinghe, Amnon Kohen,Initial Velocity Studies Comparing Heavy and Light Thymidylate Synthase,12th Annual College of Engineering research Open House Conference Proceedings, pp. 17, The University of Iowa, USA April 10th, 2014

Somarathna, T., Fernando, W.M.A.D., Ranaweera, K., Premakumara, G.A., Abeysinghe,T., Weerakkody, N. Antimicrobial activity and phytochemical screening of Alpinia malaccensis   (Ran-kiriya) against food-borne bacteriaJ. of Appl. Microbiol.,  doi: 10.1111/jam.14039

Thelma Abeysinghe, B. Hong, Zhen Wang, Amnon Kohen. (2016) Preserved Hydride Transfer Mechanism in Evolutionary Divergent Thymidylate SynthasesCurrent Topics in Biochem. Res.17, 19-30

Thelma Abeysinghe, Bradley T. Falk, Catherine Suchanek, Andrew L. Lee and Amnon Kohen, Altered Protein Motions Coupled to the Chemical Step in Heavy Thymidylate Synthase (Manuscript in preparation for Journal of American chemical Society, JACS)

AbeysingheThelma and Kohen, A. (2015) Role of Long-Range Protein Dynamics in Different Thymidylate Synthase Catalyzed Reactions, International Journal of Molecular Sciences (IJMS), 16, 7304-7319.

Ghosh, A. K., Islam, Z., Krueger, J., Abeysinghe, Thelma and Kohen, A. (2015) The general base in the thymidylate synthase catalyzed proton abstraction, Physical Chemistry Chemical Physics (PCCP), 17, 30867-30875

Singh, P.*, Abeysinghe, Thelma.* and Kohen, A. (2015) Linking Protein Motion to Enzyme CatalysisMolecules, 20, 1192-1209. (*Author’s equal contribution)

Wang, Z., Sapienza, P. J., Abeysinghe, Thelma., Luzum, C., Lee, A. L., Finer-Moore, J. S., Stroud, R. M., and Kohen, A. (2013) Mg2+ Binds to the Surface of Thymidylate Synthase and Affects Hydride Transfer at the Interior Active SiteJournal of American chemical Society, (JACS)135, 7583-7592.

Wang, Z.*, Abeysinghe, Thelma.*, Finer-Moore, J. S., Stroud, R. M., and Kohen, A. (2012) A Remote Mutation Affects the Hydride Transfer by Disrupting Concerted Protein Motions in Thymidylate SynthaseJournal of American chemical Society, (JACS)134, 17722-17730.(*Author’s equal contribution)


1)     Ranaweera B.D.P.S., Karunawardana W.A.L.S., Abeysinghe D.T., Premaratne W.A.P.J. Development of Liquid Biofertilizer System from Bio-slurry Waste and Natural Resources: A Case Study on Early Growth of Chili (Capsicum annum L.) International Conference on Applied and Pure Sciences, Faculty of Science, University of Kelaniya, Sri Lanka, 2021, p-127

2) Rajapakshe R.E.D.D.M., Karunarathne W.D.V., Abeysinghe D.T. Determination of Losartan level in human blood by HPLC, 76th Annual sessions of Sri Lanka Association for the Advancement of Science 2020, p-162

3) Alwis D.D.D.H., Abeysinghe D.T., Kumara K. A. H., Chandrika U.G.. Analysis of major carotenoids and chlorophyll pigments present in the leaves of Clausena indica, 76th Annual sessions of Sri Lanka Association for the Advancement of Science 2020, p-161

4) Abeysinghe T., Alwis D.D.D.H., Kumara, K.A.H., Chandrika U.G. In vitro assessment of antioxidant, antimicrobial and phytochemical screening of methanol leaf extract of micromelum minutum growing in Sri Lanka, PGIS Research Congress, University of Peradeniya, 2020, p-145

5) Alwis D.D.D.H., Abeysinghe D.T., Kumara K. A. H., Chandrika U.G. Analysis of major carotenoids and chlorophyll pigments present in the leaves of micromelum minutum growing in Sri Lanka, The Open University Research sessions, The Open University of Sri Lanka, 2020, p-120

6) Abeysinghe T., Kumara K.A.H., Alwis D.D.D.H., Chandrika U.G. In Vitro Assessment of Antioxidant, Antimicrobial and Phytochemical Screening of Crude Methanolic Extract of Leaves of Murraya koenigii Growing in Sri Lanka, 7th Ruhuna International Science and Technology Conference 2020, p-109

7) Abeysinghe D.T., Kaushalya K.A.D., Kumara K.A.H., Alwis D.D.D.H. Comparison of proximate analysis and selected mineral element analysis of two major species of family Rutaceae, Muraya koenigii and Micromelum minutum, 75th Annual sessions of Sri Lanka Association for the Advancement of Science 2019, p-170

8) Alwis D.D.D.H., Fernando D.D.T.H., Jayaweera P.M., Chandrika U.G., Abeysinghe D.T. UV-Vis absorption study of some carotenoids and their aggregrates extracted from natural plant materials, 75th Annual sessions of Sri Lanka Association for the Advancement of Science 2019,(p-183)

9) Weerasinghe P., Abeysinghe T., Paranagama P.A. Assesment of in-vitro antioxidant activity and flavonoid content Vernonia cinerea ,  4th International research symposium on Pure and applied Sciences Conference proceedings,  University of Kelaniya, 2019, p-173

10) Weerasinghe P, Abeysinghe T., Paranagama P.A. Comparative study on proximate and Mineral composition in Vernonina cinerea,  20th International Postgraduate Research Conference proceedings, University of Kelaniya, 2019, p-86

11) Abeysinghe D.T., Kumara K.A.H., Alwis D.D.D.H., Chandrika U.G. Assesment of proximate and mineral content of Clausena indica leaves in Sri Lanka 20th International Postgraduate Research Conference proceedings, University of Kelaniya, 2019, p-86

 12) Manohari I.D.M., Karunaratne W.D.V., Abeysinghe T. Determination of narcotic(morphine. Codeine, 6-monoacetylmorphine) levels in human urine by gas chromatography 4th International research symposium on Pure and applied Sciences Conference proceedings, University of Kelaniya,  2019, p-127

13) Ananda K Ghosh, Thelma Abeysinghe, Amnon Kohen, Altered Protein Dynamics Modified the Chemical Step in Thymidylate Synthase, Annual meeting of the American Society for Biochemistry and Molecular Biology, Chicago, USA. April 22-26th, 2017

14) Thelma Abeysinghe, Catherine Suchanek, Amnon Kohen, Experimental Studies of Enzyme Catalyzed Hydrogen-Transfer Reactions, The 34th Midwest Enzyme Chemistry Conference Proceedings,, North Western University, Illinois, USA. September 27th, 2014, p-22

15) Catherine Suchanek, Thelma Abeysinghe, Amnon Kohen, Initial Velocity Studies Comparing Heavy and Light Thymidylate Synthase,12th Annual College of Engineering research Open House Conference Proceedings, The University of Iowa, USA April 10th, 2014, p-17

16) Catherine Suchanek, Thelma Abeysinghe, Amnon Kohen, Method of Using Fast Cloning Technique to Express Thymidylate Synthase with Polyhistidine-tag to Aide in the Extraction of a Pure Protein, 13th Annual Meeting of American Institute of Chemical Engineers (AIChE), Hilton San Francisco Union Square, San Francisco, CA, USA November3-8th, 2013, p-23 

17) Thelma Abeysinghe, Amnon Kohen, Effects of a remote mutation on different chemical steps catalysed by Thymidylate Synthase, 22nd Annual Biocatalysis and Bioprocessing Conference Proceedings, The University of Iowa, USA October 21-22nd, 2013, p-34

18) Thelma Abeysinghe, Zhen Wang, Amnon Kohen, Histidine 147 and its implications on the mechanism of Thymidylate Synthase, Holden Comprehensive Cancer Centre Research Retreat Proceedings, The University of Iowa, USA. June 13th, 2013, p-112

19) Thelma Abeysinghe, Amnon Kohen, the role of protein’s long range dynamics transfer in Thymidylate Synthase catalysed reactions, The 33rd Midwest Enzyme Chemistry Conference Proceedings, Loyola University, Chicago, USA. October 12th, 2013, p-21

20) Thelma Abeysinghe, Zhen Wang, Amnon Kohen, Effects of a Remote Mutation on the hydride transfer step in Thymidylate Synthase ,47th American Chemical Society (ACS) Midwest Regional Conference Proceedings, Omaha, USA, October 24-27th, 2012, p-32

21) Thelma Abeysinghe, Zhen Wang, Amnon Kohen, Effects of Y209W on the hydride transfer step catalysed in Thymidylate Synthase, Holden Comprehensive Cancer Centre Research Retreat Proceedings, The University of Iowa, USA. June 14th, 2012, p-12

22) Thelma Abeysinghe, Zhen Wang, Amnon Kohen, Long Range Protein Effects of Thymidylate Synthase, The 31st Midwest Enzyme Chemistry Conference Proceedings, University of Chicago, Chicago, USA. October 15th, 2011, p-18

23) Thelma Abeysinghe, Zhen Wang, Amnon Kohen, Purification of R-6xH] – N5, N10 –methylene-5,6,7,8-tetrahydrofolate for studies of Thymidylate Synthase, The 30th Midwest Enzyme Chemistry Conference Proceedings, North Western University, Illinois, USA. October 16th, 2010, p-17

 



 

  • Life-Member, Section E-2 (Chemical Sciences), Sri Lanka Association for the Advancement of Science (SLAAS), Sri Lanka 
  • Life-Member, Institute of Chemistry Ceylon (IChem) 
  • Member, American Chemical Society (ACS) 
  • Life-Member, College of Biochemists (CBSL) 
  • Life-Member, Organization for Women in Science for the Developing World (OWSD) 
  • Life-Member, Buckyball Society, Department of Chemistry, The Open University of Sri Lanka 

Served  as a Member of the Subject committee working on the Subject Benchmark Statement on Microbiology/Molecular Biology/biochemistry at the University Grants Commission (June 2020 to date) 


 

  • McCloskey Research Award by the University of Iowa, USA, 2013
  • Graduate College Summer Fellowship Award by the University of Iowa, USA, 2013
  • Spring Travel Grant Award from the Executive Council of Graduate & Professional Students (ECGPS), University of Iowa, USA, 2014
  • Spring Travel Grant Award from the Graduate Students Senate (GSS),University of Iowa, USA,  2014
  • Research Awards, The Open University of Sri Lanka, 2022

 

Life-Member, Section E-2 (Chemical Sciences), Sri Lanka Association for the Advancement of Science (SLAAS), Sri Lanka 

Life-Member, Institute of Chemistry Ceylon (IChem) 

Member, American Chemical Society (ACS) 

Life-Member, College of Biochemists (CBSL) 

Life-Member, Organization for Women in Science for the Developing World (OWSD) 

Life-Member, Buckyball Society, Department of Chemistry, The Open University of Sri Lanka