Sökning: onr:"swepub:oai:DiVA.org:lnu-87498" >
Biophysical studies...
Biophysical studies of the actin-myosin motor system and applications in nanoscience
-
- Rahman, Mohammad A. (författare)
- Linnéuniversitetet,Institutionen för kemi och biomedicin (KOB),The Molecular motor and bionano-group
-
- Månsson, Alf, professor (preses)
- Linnéuniversitetet,Institutionen för kemi och biomedicin (KOB)
-
- Oiwa, Kazuhiro, Distinguished researcher and the fellow of NICT (opponent)
- National Institute of Information and Communications Technology (NICT), Kobe 651-2492, Japan.
-
(creator_code:org_t)
- ISBN 9789188898821
- Växjö : Linnaeus University Press, 2019
- Engelska 121 s.
-
Serie: Linnaeus University Dissertations ; 359
- Relaterad länk:
-
https://lnu.diva-por... (primary) (Raw object)
-
visa fler...
-
https://lnu.diva-por... (Preview)
-
https://urn.kb.se/re...
-
visa färre...
Abstract
Ämnesord
Stäng
- The actin-myosin motor system plays important roles in cellular processes. In addition, actin and myosin have been used for developments towards nanotechnological applications in recent years. Therefore, fundamental biophysical studies of actin and myosin and the actomyosin force generating cycle are important both in biology and for nanotechnology where the latter applications require methodological insights for optimization. This dual goal is central in the present thesis with major focus on factors that control the function (e.g. velocity) and the effectiveness of transport of filaments (e.g. filament flexural rigidity) through nanoscale channels with supplementation of methodological insights. The thesis thus provides evidence that actin is a dynamic filament whose flexural rigidity is different at different MgATP concentrations as well as in the presence or absence of myosin binding. Furthermore, probing the myosin ATPase cycle with the myosin inhibitor blebbistatin revealed that velocity is easily modified by this drug. Our detailed studies also suggest that actin-myosin force generation is preceded by Pi release and that blebbistatin changes the rate limiting transition in the cycle from the attachment step to a step between weakly attached states. The studies of actin dynamics and of the actomyosin force generating cycle were largely performed using in vitro motility assay (IVMA) where surface adsorbed myosin motor or its proteolytic fragments propel fluorescently labeled actin filaments. The IVMA is often taken as the basis for developments towards different nanotechnological applications. However, in the IVMA, actomyosin motility is often negatively affected by the presence of “dead”, non-functional myosin heads. Therefore, in this thesis, two popular methods, that are often used to remove dead myosin heads, are analyzed and compared. It was found that after affinity purification, the in vitro actin sliding velocity is reduced compared to the control conditions, something that was not seen with the use of blocking actin. Therefore, the effects of the affinity purification method should be considered when interpreting IVMA data. This is important while using IVMA both for fundamental studies and for nanotechnological applications. Another issue in the use of IVMAs in nanotechnological applications is the requirement for expensive and time-consuming fabrication of nanostructured devices. We therefore developed a suitable method for regenerating molecular motor based bionanodevices without a need to disassemble the flow cell. Evidence is presented that, use of proteinase K with a suitable detergent (SDS or Triton X100) lead to successful regeneration of devices where both actin-myosin and microtubule-kinesin motility are used. Lastly, this thesis presents efforts to immobilize engineered light sensitive myosin motors on trimethyl chlorosilane (TMCS) derivatized surfaces for light operated switching of myosin motor in order to control actin movement in nano-networks. This has potential for developing a programmable junction in a biocomputation network. In brief, the described results have contributed both to the fundamental understanding of actin and myosin properties and the actomyosin interaction mechanisms. They have also given technical insights for molecular motor based bionanotechnology.
Ämnesord
- MEDICIN OCH HÄLSOVETENSKAP -- Medicinska och farmaceutiska grundvetenskaper -- Mikrobiologi inom det medicinska området (hsv//swe)
- MEDICAL AND HEALTH SCIENCES -- Basic Medicine -- Microbiology in the medical area (hsv//eng)
- NATURVETENSKAP -- Biologi -- Biofysik (hsv//swe)
- NATURAL SCIENCES -- Biological Sciences -- Biophysics (hsv//eng)
- TEKNIK OCH TEKNOLOGIER -- Nanoteknik (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Nano-technology (hsv//eng)
Nyckelord
- myosin II
- actin
- actomyosin force generating cycle
- blebbistatin
- in vitro motility assay
- actin affinity purification
- blocking actin
- bionanodevices
- proteinase k
- SDS
- triton X100
- surface recycling
- engineered myosin motor
- programmable gate
- biocomputation.
- Biomedical Sciences
- Biomedicinsk vetenskap
Publikations- och innehållstyp
- vet (ämneskategori)
- dok (ämneskategori)
Hitta via bibliotek
Till lärosätets databas