Do Water Molecules Displaced by Hydrophobic Interactions Stabilize Antigen-Antibody Binding? Physico-chemical background of antigen-antibody reactions analyzed by fluorescent and Fourier-transform infrared spectroscopy on FITC – anti-FITC (IgG1) model
BACKGROUND: Antigen-antibody reactions are a special field of molecular interactions. The physico-chemical nature of antigen-antibody binding and ligand-induced changes in the fine molecular structures of antigens during immunocomplex formation are less studied. However, these changes in the molecul...
| Main Author: | |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Faculty of Medicine Osijek
2022-11-01
|
| Series: | Southeastern European Medical Journal |
| Subjects: | |
| Online Access: | http://seemedj.mefos.unios.hr/index.php/seemedj/article/view/257/145 |
| _version_ | 1811211547906670592 |
|---|---|
| author | Peter Nemeth |
| author_facet | Peter Nemeth |
| author_sort | Peter Nemeth |
| collection | DOAJ |
| description | BACKGROUND: Antigen-antibody reactions are a special field of molecular interactions. The physico-chemical nature of antigen-antibody binding and ligand-induced changes in the fine molecular structures of antigens during immunocomplex formation are less studied. However, these changes in the molecular appearance are extremely important for further molecular recognition. The major aim of this study is to clarify the physico-chemical modification of the antigen/hapten during immunobinding using model experiments.
METHODS: An appropriate model system was designed for our investigations: fluorescein-iso-thiocyanate (FITC, isomer I) was used as the antigen (hapten), and its interactions with a specific antibody (monoclonal anti-FITC IgG1) were analyzed using spectrophotometry, different spectrofluorimetric methods and fluorescence polarization, and Fourier-transform infrared spectroscopic methods.
RESULTS: Fluorescent polarization and infrared spectroscopic measurements detected a local decrease in the hydration degree in the submolecular area of the specific ligand between the small antigen (hapten) molecule and the hypervariable region of the specific IgG1, causing “rigidization” of molecular movements. Changes in hydration modified the molecular microenvironment, allowing them to influence further functions of both immunoglobulins and the antigen.
CONCLUSION: Hydrophobic interactions with exclusion of water molecules around the binding sites seem to be thermodynamically strong enough for stable molecular binding without a covalent chemical interaction between the antigen and the antibody. The results of this study, together with data obtained in previous research, help understand the molecular dynamics of the antigen-antibody reaction better. |
| first_indexed | 2024-04-12T05:15:53Z |
| format | Article |
| id | doaj.art-58a3c1af3aca472b989f4d8040ce9907 |
| institution | Directory Open Access Journal |
| issn | 2459-9484 |
| language | English |
| last_indexed | 2024-04-12T05:15:53Z |
| publishDate | 2022-11-01 |
| publisher | Faculty of Medicine Osijek |
| record_format | Article |
| series | Southeastern European Medical Journal |
| spelling | doaj.art-58a3c1af3aca472b989f4d8040ce99072022-12-22T03:46:38ZengFaculty of Medicine OsijekSoutheastern European Medical Journal2459-94842022-11-016211910.26332/seemedj.v6i2.257Do Water Molecules Displaced by Hydrophobic Interactions Stabilize Antigen-Antibody Binding? Physico-chemical background of antigen-antibody reactions analyzed by fluorescent and Fourier-transform infrared spectroscopy on FITC – anti-FITC (IgG1) modelPeter Nemeth0Department of Immunology and Biotechnology, Clinical Centre, University of Pecs Medical School, Pecs, HungaryBACKGROUND: Antigen-antibody reactions are a special field of molecular interactions. The physico-chemical nature of antigen-antibody binding and ligand-induced changes in the fine molecular structures of antigens during immunocomplex formation are less studied. However, these changes in the molecular appearance are extremely important for further molecular recognition. The major aim of this study is to clarify the physico-chemical modification of the antigen/hapten during immunobinding using model experiments. METHODS: An appropriate model system was designed for our investigations: fluorescein-iso-thiocyanate (FITC, isomer I) was used as the antigen (hapten), and its interactions with a specific antibody (monoclonal anti-FITC IgG1) were analyzed using spectrophotometry, different spectrofluorimetric methods and fluorescence polarization, and Fourier-transform infrared spectroscopic methods. RESULTS: Fluorescent polarization and infrared spectroscopic measurements detected a local decrease in the hydration degree in the submolecular area of the specific ligand between the small antigen (hapten) molecule and the hypervariable region of the specific IgG1, causing “rigidization” of molecular movements. Changes in hydration modified the molecular microenvironment, allowing them to influence further functions of both immunoglobulins and the antigen. CONCLUSION: Hydrophobic interactions with exclusion of water molecules around the binding sites seem to be thermodynamically strong enough for stable molecular binding without a covalent chemical interaction between the antigen and the antibody. The results of this study, together with data obtained in previous research, help understand the molecular dynamics of the antigen-antibody reaction better.http://seemedj.mefos.unios.hr/index.php/seemedj/article/view/257/145antigen-antibody reactionfitcfluorescencespectrum analysis |
| spellingShingle | Peter Nemeth Do Water Molecules Displaced by Hydrophobic Interactions Stabilize Antigen-Antibody Binding? Physico-chemical background of antigen-antibody reactions analyzed by fluorescent and Fourier-transform infrared spectroscopy on FITC – anti-FITC (IgG1) model Southeastern European Medical Journal antigen-antibody reaction fitc fluorescence spectrum analysis |
| title | Do Water Molecules Displaced by Hydrophobic Interactions Stabilize Antigen-Antibody Binding? Physico-chemical background of antigen-antibody reactions analyzed by fluorescent and Fourier-transform infrared spectroscopy on FITC – anti-FITC (IgG1) model |
| title_full | Do Water Molecules Displaced by Hydrophobic Interactions Stabilize Antigen-Antibody Binding? Physico-chemical background of antigen-antibody reactions analyzed by fluorescent and Fourier-transform infrared spectroscopy on FITC – anti-FITC (IgG1) model |
| title_fullStr | Do Water Molecules Displaced by Hydrophobic Interactions Stabilize Antigen-Antibody Binding? Physico-chemical background of antigen-antibody reactions analyzed by fluorescent and Fourier-transform infrared spectroscopy on FITC – anti-FITC (IgG1) model |
| title_full_unstemmed | Do Water Molecules Displaced by Hydrophobic Interactions Stabilize Antigen-Antibody Binding? Physico-chemical background of antigen-antibody reactions analyzed by fluorescent and Fourier-transform infrared spectroscopy on FITC – anti-FITC (IgG1) model |
| title_short | Do Water Molecules Displaced by Hydrophobic Interactions Stabilize Antigen-Antibody Binding? Physico-chemical background of antigen-antibody reactions analyzed by fluorescent and Fourier-transform infrared spectroscopy on FITC – anti-FITC (IgG1) model |
| title_sort | do water molecules displaced by hydrophobic interactions stabilize antigen antibody binding physico chemical background of antigen antibody reactions analyzed by fluorescent and fourier transform infrared spectroscopy on fitc anti fitc igg1 model |
| topic | antigen-antibody reaction fitc fluorescence spectrum analysis |
| url | http://seemedj.mefos.unios.hr/index.php/seemedj/article/view/257/145 |
| work_keys_str_mv | AT peternemeth dowatermoleculesdisplacedbyhydrophobicinteractionsstabilizeantigenantibodybindingphysicochemicalbackgroundofantigenantibodyreactionsanalyzedbyfluorescentandfouriertransforminfraredspectroscopyonfitcantifitcigg1model |