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Feedback Controlled Optical Tweezers for Measuring Lambda Exonuclease Activity

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dc.contributor Helsingin yliopisto, matemaattis-luonnontieteellinen tiedekunta, fysiikan laitos fi
dc.contributor Helsingfors universitet, matematisk-naturvetenskapliga fakulteten, institutionen för fysik sv
dc.contributor University of Helsinki, Faculty of Science, Department of Physics, Materiaalifysiikan osasto en
dc.contributor.author Ojala, Heikki fi
dc.date.accessioned 2012-02-27T10:30:24Z
dc.date.available 2012-02-22 fi
dc.date.available 2012-02-27T10:30:24Z
dc.date.issued 2011-09-13 fi
dc.identifier.uri URN:NBN:fi-fe201202271458 fi
dc.identifier.uri http://hdl.handle.net/10138/29987
dc.description.abstract A single molecule is enough to initiate a biological function. Therefore methods to study single biomolecules are important. By measuring one biomolecule at a time it is possible to reveal the differences from molecule to molecule. Moreover, with these methods one can measure short-lived non-equilibrium states of the molecules. An optical tweezers instrument for single molecule experiments was modified to permit constant force experiments. The resulting force-clamp control was then used to measure enzymatic activity of the molecular motor lambda exonuclease at different temperatures. The force-clamp experiments were performed in a dumbbell geometry where two polystyrene spheres are connected by a DNA molecule. A single continuous wave laser source created the dual trap optical tweezers with one stationary and one steerable trap. Acousto-optic deflectors steered the trap according to a digital feedback control from a field programmable gate array. Using the feedback control, at 1.3±0.3 pN force, the lambda exonuclease reaction rate was measured to be 23±16 nt/s at 25±1°C and 54±15 nt/s at 37±1°C. The most important achievement in this thesis was the detected increase in the reaction rate of lambda exonuclease due to the increased temperature. Thus, the real-time force- clamp control opens up new possibilities to study the molecular machinery that generates forces and movements in living organisms. en
dc.language.iso en fi
dc.publisher Helsingin yliopisto fi
dc.publisher Helsingfors universitet sv
dc.publisher University of Helsinki en
dc.rights Julkaisu on tekijänoikeussäännösten alainen. Teosta voi lukea ja tulostaa henkilökohtaista käyttöä varten. Käyttö kaupallisiin tarkoituksiin on kielletty. fi
dc.rights This publication is copyrighted. You may download, display and print it for Your own personal use. Commercial use is prohibited. en
dc.rights Publikationen är skyddad av upphovsrätten. Den får läsas och skrivas ut för personligt bruk. Användning i kommersiellt syfte är förbjuden. sv
dc.title Feedback Controlled Optical Tweezers for Measuring Lambda Exonuclease Activity en
dc.type.ontasot Lisensiaatintyö fi
dc.type.ontasot Licentiate thesis en
dc.type.ontasot Licentiatsavhandling sv
dc.ths Ziedaite, Gabija fi
dc.ths Wallin, Anders fi
dc.type.dcmitype Text fi

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