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| Registros recuperados: 14 | |
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| Andy Maloney; Lawrence J. Herskowitz; Steven J. Koch. |
| The molecular motor kinesin-1, an ATPase, and the substrate it walks along, microtubules, are vital components of eukaryotic cells. Kinesin converts chemical energy to linear motion as its two motor domains step along microtubules in a process similar to how we walk. Cells create systems of microtubules that direct the motion of kinesin. This directed motion allows kinesin to transport various cargoes inside cells.

During the stepping process, the kinesin motor domains bind and unbind from their binding sites on the microtubules. Binding and unbinding rates of biomolecules are highly dependent on hydration and exclusion of water from the binding interface. Osmotic stress will likely strongly affect the binding and... |
| Tipo: Poster |
Palavras-chave: Molecular Cell Biology. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/4469/version/3 |
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| Andy Maloney; Lawrence J. Herskowitz; Steven J. Koch. |
| We show here the effects of heavy-hydrogen water (^2^H~2~O) and heavy-oxygen water (H~2~^18^O) on the gliding speed of microtubules on kinesin-1 coated surfaces. Increased fractions of isotopic waters used in the motility solution decreased the gliding speed of microtubules by a maximum of 21% for heavy-hydrogen and 5% for heavy-oxygen water. We discuss possible interpretations of these results and the importance for future studies of water effects on kinesin and microtubules. We also discuss the implication for biomolecular devices incorporating molecular motors. |
| Tipo: Manuscript |
Palavras-chave: Molecular Cell Biology. |
| Ano: 2012 |
URL: http://precedings.nature.com/documents/7004/version/1 |
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| Steven J. Koch; Andy Maloney; Lawrence J. Herskowitz. |
| The osmotic pressure and kinetic properties of water play important roles in biomolecular interactions. As pointed out by Parsegian, Rand, and Rau, these crucial roles are often overlooked[1]. In some fields, osmotic stress and isotope effects have been exploited for probing the role water plays in binding interactions of biomolecules. To our knowledge, there have been no studies of osmotic stress and water isotope effects for kinesin, and only a handful for myosin. We're currently using the gliding motility assay to see whether we can extract new information about kinesin-1 / microtubule interactions by changing osmotic stress and water isotopes. We will describe our open-source, automated analysis platform for extracting microtubule gliding... |
| Tipo: Presentation |
Palavras-chave: Molecular Cell Biology. |
| Ano: 2010 |
URL: http://precedings.nature.com/documents/4479/version/1 |
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| Andy Maloney; Lawrence J. Herskowitz; Steven J. Koch. |
| The molecular motor kinesin-1, an ATPase, and the substrate it walks along, microtubules, are vital components of eukaryotic cells. Kinesin converts chemical energy to linear motion as its two motor domains step along microtubules in a process similar to how we walk. Cells create systems of microtubules that direct the motion of kinesin. This directed motion allows kinesin to transport various cargos inside cells.

During the stepping process, the kinesin motor domains bind and unbind from their binding sites on the microtubules. Binding and unbinding rates of biomolecules are highly dependent on hydration and exclusion of water from the binding interface. Osmotic stress will likely strongly affect the binding and... |
| Tipo: Poster |
Palavras-chave: Molecular Cell Biology. |
| Ano: 2010 |
URL: http://precedings.nature.com/documents/4469/version/1 |
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| Steven J. Koch; Andy Maloney; Lawrence J. Herskowitz. |
| The osmotic pressure and kinetic properties of water play important roles in biomolecular interactions. As pointed out by Parsegian, Rand, and Rau, these crucial roles are often overlooked[1]. In some fields, osmotic stress and isotope effects have been exploited for probing the role water plays in binding interactions of biomolecules. To our knowledge, there have been no studies of osmotic stress and water isotope effects for kinesin, and only a handful for myosin. We're currently using the gliding motility assay to see whether we can extract new information about kinesin-1 / microtubule interactions by changing osmotic stress and water isotopes. We will describe our open-source, automated analysis platform for extracting microtubule gliding... |
| Tipo: Presentation |
Palavras-chave: Molecular Cell Biology. |
| Ano: 2010 |
URL: http://precedings.nature.com/documents/4479/version/2 |
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| Andy Maloney; Lawrence J. Herskowitz; Steven J. Koch. |
| The molecular motor kinesin-1, an ATPase, and the substrate it walks along, microtubules, are vital components of eukaryotic cells. Kinesin converts chemical energy to linear motion as its two motor domains step along microtubules in a process similar to how we walk. Cells create systems of microtubules that direct the motion of kinesin. This directed motion allows kinesin to transport various cargos inside cells.

During the stepping process, the kinesin motor domains bind and unbind from their binding sites on the microtubules. Binding and unbinding rates of biomolecules are highly dependent on hydration and exclusion of water from the binding interface. Osmotic stress will likely strongly affect the binding and... |
| Tipo: Poster |
Palavras-chave: Molecular Cell Biology. |
| Ano: 2010 |
URL: http://precedings.nature.com/documents/4469/version/2 |
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| Lawrence J. Herskowitz; Anthony L. Salvagno; R. Andy Maloney; Linh N. Le; Steven J. Koch. |
| Ability to map polymerases and nucleosomes on chromatin is important for understanding the impact of chromatin remodeling on key cellular processes. Current methods (such as ChIP and ChIP-chip) have produced a wealth of information that demonstrates this importance, but key information is elusive in these ensemble methods. We’re pursuing a new single-molecule chromatin mapping method based on unzipping native chromatin molecules with optical tweezers. The first step we are taking towards this ability is shotgun DNA mapping (SDM). This is the ability to identify the genomic location of a random DNA fragment based on its naked DNA unzipping forces compared with simulated unzipping forces of a published genome. We show that ~32 separate... |
| Tipo: Manuscript |
Palavras-chave: Biotechnology; Genetics & Genomics. |
| Ano: 2010 |
URL: http://precedings.nature.com/documents/2808/version/2 |
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| Lawrence J. Herskowitz; Anthony L. Salvagno; Brian P. Josey; Andy Maloney; Steven J. Koch. |
| Kinesin-1 (conventional kinesin) is a homodimeric motor protein important for axonal transport. It has been well studied through ensemble and single-molecule assays. However, the enzymatic stepping cycle is complex, with many rate constants that are modulated by interaction of the two motor domains. This makes it difficult to predict how changes in a given rate constant may affect observable properties such as processivity, velocity, or stall force. We have written a simulation of kinesin walking using a Stochastic Simulation Algorithm. The model allows for interactions between the heads, and includes states that are not considered part of the normal cycle. This adds to the complexity of the model but also allows for probing rare events, such as those that... |
| Tipo: Poster |
Palavras-chave: Molecular Cell Biology. |
| Ano: 2010 |
URL: http://precedings.nature.com/documents/4468/version/1 |
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| Steven J. Koch; Lawrence J. Herskowitz. |
| Kinesin-1 is a homodimeric molecular motor protein that uses ATP and a hand-over-hand motion to transport cargo along microtubules. How kinesin converts chemical energy into directed motion is a question that has been actively studied since its discovery. Even at the most coarse-grained level of chemical kinetics, understanding is still lacking. Minimal kinetic models are often developed to both explain kinesin’s hand-over-hand forward-stepping behavior and to infer important kinetic rate constants from experimental data. These minimal models are often limited to a handful of two-headed states on a core cycle and have been essential for the current level of understanding. However, it is not always clear how to evolve these core-cycle models to... |
| Tipo: Manuscript |
Palavras-chave: Molecular Cell Biology. |
| Ano: 2010 |
URL: http://precedings.nature.com/documents/5038/version/1 |
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| Andy Maloney; Lawrence J. Herskowitz; Steven J. Koch. |
| In this study, we report differences in the observed gliding speed of microtubules dependent on the choice of bovine casein used as a surface passivator. We observed differences in both speed and support of microtubules in each of the assays. Whole casein, comprised of [alpha]~s1~, [alpha]~s2~, [beta], and [kappa] casein, supported motility and averaged speeds of 966 ± 7 nm/s. Alpha casein can be purchased as a combination of s1 and s2 and supported gliding motility and average speeds of 949 ± 4 nm/s. Beta casein did not support motility very well and averaged speeds of 870 ± 30 nm/s. Kappa casein supported motility very poorly and we were unable to obtain an average speed. Finally, we observed that mixing alpha, beta, and kappa... |
| Tipo: Manuscript |
Palavras-chave: Molecular Cell Biology. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/5278/version/2 |
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| Andy Maloney; Lawrence J. Herskowitz; Steven J. Koch. |
| In this study, we report differences in the observed gliding speed of microtubules
dependent on the choice of bovine casein used as a surface passivator. We observed
differences in both speed and support of microtubules in each of the assays. Whole
casein, comprised of [alpha]~s1~, [alpha]~s2~, [beta], and [kappa] casein, supported motility and averaged speeds of
966 ± 7 nm/s. Alpha casein can be purchased as a combination of s1 and s2 and
supported gliding motility and average speeds of 949 ± 4 nm/s. Beta casein did not
support motility very well and averaged speeds of 870 ± 30 nm/s. Kappa casein
supported... |
| Tipo: Manuscript |
Palavras-chave: Molecular Cell Biology. |
| Ano: 2010 |
URL: http://precedings.nature.com/documents/5278/version/1 |
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| Steven J. Koch; Andy Maloney; Lawrence J. Herskowitz. |
| The osmotic pressure and kinetic properties of water play important roles in biomolecular interactions. As pointed out by Parsegian, Rand, and Rau, these crucial roles are often overlooked[1]. In some fields, osmotic stress and isotope effects have been exploited for probing the role water plays in binding interactions of biomolecules. To our knowledge, there have been no studies of osmotic stress and water isotope effects for kinesin, and only a handful for myosin. We're currently using the gliding motility assay to see whether we can extract new information about kinesin-1 / microtubule interactions by changing osmotic stress and water isotopes. We will describe our open-source, automated analysis platform for extracting microtubule gliding... |
| Tipo: Presentation |
Palavras-chave: Molecular Cell Biology. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/4479/version/3 |
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| Lawrence J. Herskowitz; Anthony L. Salvagno; R. Andy Maloney; Linh N. Le; Steven J. Koch. |
| Ability to map polymerases and nucleosomes on chromatin is important for understanding the impact of chromatin remodeling on key cellular processes. Current methods (such as ChIP and ChIP-chip) have produced a wealth of information that demonstrates this importance, but key information is elusive in these ensemble methods. We’re pursuing a new single-molecule chromatin mapping method based on unzipping native chromatin molecules with optical tweezers. The first step we are taking towards this ability is shotgun DNA mapping (SDM). This is the ability to identify the genomic location of a random DNA fragment based on its naked DNA unzipping forces compared with simulated unzipping forces of a published genome. We show that ~32 separate... |
| Tipo: Manuscript |
Palavras-chave: Biotechnology; Genetics & Genomics. |
| Ano: 2009 |
URL: http://precedings.nature.com/documents/2808/version/1 |
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| Registros recuperados: 14 | |
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