Elastic Model of Spirochete Morphology and Motility

螺旋体形态和运动的弹性模型

• 批准号: 6828744
• 负责人: CHARLES W WOLGEMUTH
• 金额: $ 26.85万
• 依托单位: UNIVERSITY OF CONNECTICUT SCH OF MED/DNT
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-05-01 至 2008-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6828744
• 关键词: Borrelia; Spirochaetales; bacteria characteristic; cell component structure /function; cell morphology; cell motility; cell wall; elasticity; flagellum; mathematical model; model design /development; periplasm

DESCRIPTION (provided by applicant): Polymer filaments play a major role in bacterial motility and morphology. Spirochetes, bacteria that swim by rotating helical flagella that are encased within a periplasmic space (the space between the inner and outer cell membranes where the cell wall material is located), are excellent model systems to study how elastic polymer filaments coupled to a bacterial cell wall can affect motility and morphology. Rotation of the flagella induces rotation and deformations in the cell wall. Because the flagella remain within the periplasm, the elasticity of the helical flagella competes with the preferred morphology of the cell wall. How this interplay between flagella and wall elasticity leads to total cell morphology and how forces developed by the flagellar motor drive motility is poorly understood. This grant will support the broadening of elastohydrodynamics to handle systems in which two or more elastic filaments are coupled together. This new mathematical framework will then be employed to model the morphology and motility of spirochete bacteria. Through study of the static shapes predicted by this model, this work will test the experimentally justified hypothesis that the flagella and cell wall are the dominant morphological determinants in spirochete bacteria and explore how the number and length of the periplasmic flagella affect these shapes. A detailed analysis of how this system responds to external forces and torques, as would be produced by the flagellar motor, will lead to an understanding of the dynamic shape changes that spirochetes undergo while swimming. Finally, the coupling of the resulting cell conformations to the viscous fluid environment surrounding them will be investigated to quantify the propulsive force generated by the rotation of the flagellar motor for many spirochetes and also explain the precession of the flat wave morphology in Borrelia burgdorferi. This grant will also support the experimental measurement of the bending moduli of the cell wall and the periplasmic flagella.

描述（由申请人提供）：聚合物丝在细菌运动和形态学中起主要作用。螺旋体，通过旋转螺旋鞭毛游泳的细菌，这些蛋白鞭毛被包裹在周质空间（细胞壁材料所在的内部和外部细胞膜之间的空间），是研究如何耦合到细菌细胞壁与细菌细胞壁耦合的弹性模型系统的出色模型系统。鞭毛的旋转会导致细胞壁旋转和变形。由于鞭毛保留在周期内，因此螺旋鞭毛的弹性与细胞壁的首选形态竞争。鞭毛和壁弹性之间的这种相互作用如何导致总细胞形态以及鞭毛运动驱动运动发展的力如何被熟悉。 该赠款将支持扩大弹性水力动力学，以处理将两个或多个弹性丝耦合在一起的系统。然后，将采用这个新的数学框架来对螺旋体细菌的形态和运动进行建模。通过研究该模型预测的静态形状，这项工作将检验实验合理的假设，即鞭毛和细胞壁是螺旋体细菌中主要的形态决定因素，并探索骨质鞭毛的数量和长度如何影响这些形状。对鞭毛电动机所产生的外部力和扭矩如何响应该系统如何响应该系统的详细分析将导致人们对螺旋体在游泳时发生的动态形状变化的理解。最后，将研究所得细胞与周围粘性流体环境的构型的耦合，以量化许多螺旋体的鞭毛电动机旋转产生的推进力，并解释了Borrelia burgdorferi中扁平波形态的预测。该赠款还将支持细胞壁和周质鞭毛的弯曲模量的实验测量。