Journal of mechanochemistry & cell motility最新文献_第3页

Locomotion of flagellates with mastigonemes. 鞭毛虫的运动与雄蕊。

Journal of mechanochemistry & cell motility Pub Date : 1976-03-01

C Brennen

{"title":"Locomotion of flagellates with mastigonemes.","authors":"C Brennen","doi":"","DOIUrl":"","url":null,"abstract":"Theoretical hydrodynamic analyses of the locomotion of flagellates with mastigonemes are presented and particular comparison is made within experimental data on Ochromonas malhamensis. The first part of the paper analyses locomotion assuming the mastigonemes are rigid and maintain a fixed and normal position relative to the flagellum. The predicted propulsive velocity of 60 mum/sec for Ochromonas agrees well with the observed values of 55-60 mum/sec. It is shown that the propulsive system of Ochromonas represents a compromise between the need for efficient rectilinear propulsion and the need to manoeuvre and accelerate. The effect of rigid mastigonemes which are maintained at non-zero angles to the flagellar normal is also calculated and demonstrates a significant degradation of performance when this angle is greater than about 10 degrees. The latter part of the paper investigates the more complex but more realistic situation in which the mastigonemes flex during the motion according to the instantaneous hydrodynamic forces imposed upon them. The cyclical flexing history of a mastigoneme with passage of a flagellar wave and the consequent velocity of propulsion are obtained for a variety of geometric configurations and structural mastigoneme stiffnesses. It is demonstrated that there exists a relatively small transition range in the values of mastigoneme flexibility below which the mastigonemes are essentially rigid and above which they become totally ineffective hydrodynamically so that the flagellum can be regarded as essentially smooth. Since the transition value of the modulus of elasticity is about 5 dynes/mum2 (or stiffness of 3.5 X 10(-16) dyne cm2) for the mastigonemes of Ochromonas it would appear that the actual value must be in excess of this. Comparison is made with the structural properties of the micro-tubules in eukaryote cilia and flagella and with prokaryote flagella. The latter comparison suggests that the mastigonemes of Ochromonas are just rigid enough to produce the observed propulsive effect.","PeriodicalId":76011,"journal":{"name":"Journal of mechanochemistry & cell motility","volume":"3 3","pages":"207-17"},"PeriodicalIF":0.0,"publicationDate":"1976-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12128917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparative studies on the structure and aggregative properties of the myosin molecule. I. The structure of the lobster myosin molecule. 肌球蛋白分子结构和聚集特性的比较研究。龙虾肌球蛋白分子的结构。

Journal of mechanochemistry & cell motility Pub Date : 1976-03-01

R F Siemankowski, C R Zobel

{"title":"Comparative studies on the structure and aggregative properties of the myosin molecule. I. The structure of the lobster myosin molecule.","authors":"R F Siemankowski, C R Zobel","doi":"","DOIUrl":"","url":null,"abstract":"Myosin purified from the abdominal flexor muscle of the lobster, Homarus americanus, has a number average length of 1559 +/- 218 A, a rod like tail 1335 A long and a globular head 225 X 45 A as determined from electron microscopic observations on platinum shadowed preparations. The mass of the molecule was determined to be ca. 486,000 daltons from high speed equilibrium centrifugation studies at neutral and alkaline pH, and by SDS-acrylamide gel electrophoresis. Both sedimentation equilibrium centrifuge studies at alkaline pH and SDS-acrylamide gel electrophoresis experiments, indicate that the molecule contains a heavy chain core (two polypeptide chains weighing ca. 210,000 daltons each) and ca. four light chains of two weight classes (ca. 16,000 and 20,000 daltons). The amino acid composition of the myosin was determined. The specific activities of the Mg2+ -activated, K+/EDTA-activated, and Ca2+ -activated ATPases of the myosin were determined. Kinetic analysis of the digestion of lobster myosin with trypsin suggests that lobster myosin contains three classes of lysine and arginine residues; slowly split (k = 2.07 +/- 0.31 X 10(-2) moles/min2), rapidly split (k = 11.0 +/- 1.83 X 10(-2) moles/min2) and trypsin insensitive. There are 187 +/- 22 slowly split residues, 280 +/- 35 rapidly split residues, and 144 +/- 41 trypsin insensitive bonds per molecule. Comparison of these molecular parameters with those for the vertebrate skeletal muscle myosin indicates that the two myosins are similar in terms of mass, shape and overall polypeptide chain composition but may be considerably different in terms of local polypeptide chain conformation or composition.","PeriodicalId":76011,"journal":{"name":"Journal of mechanochemistry & cell motility","volume":"3 3","pages":"171-84"},"PeriodicalIF":0.0,"publicationDate":"1976-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11351451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Sarcomere length changes during stimulation of frog semitendinosus muscle. 刺激蛙半腱肌时肌节长度的变化。

Journal of mechanochemistry & cell motility Pub Date : 1976-03-01

J Borejdo, P Mason

引用次数: 0

Mechanochemical coupling in flagella. IV. Absence of coupling between metabolism and motility in Chaetopterus spermatozoa. 鞭毛的机械化学耦合。IV.毛羽精子的代谢和运动之间缺乏耦合。

Journal of mechanochemistry & cell motility Pub Date : 1976-03-01

C J Brokaw, B Benedict

引用次数: 0

Cinemicrographic analysis of the movement of flagellated bacteria. II. The ratio of the propulsive velocity to the frequency of the wave propagation along flagellar tail. 鞭毛细菌运动的电影显微摄影分析。2推进速度与波浪沿鞭毛尾部传播的频率之比。

Journal of mechanochemistry & cell motility Pub Date : 1976-03-01

K Shimada, T Ikkai, T Yoshida, S Asakura

{"title":"Cinemicrographic analysis of the movement of flagellated bacteria. II. The ratio of the propulsive velocity to the frequency of the wave propagation along flagellar tail.","authors":"K Shimada, T Ikkai, T Yoshida, S Asakura","doi":"","DOIUrl":"","url":null,"abstract":"We took cinemicrographs of the movement of the flagellar tail of the peritrichously flagellated bacterium, Salmonella, swimming in a medium containing methylcellulose under a dark-ground microscope. By analysing the film, the velocity of translation u, the frequency of the propagation of helical waves along the tail fF and the frequency of the induced rotation of bacterial body fB of individual organism were measured and the experimental values of the ratios u/fF, u/fB and fF/fB were obtained. On the other hand, the theoretical values of these ratios were calculated by inserting the geometrical parameters describing the shapes and the sizes of the body and the tail of individual organism into the equations previously derived for the hydrodynamic model of the propulsion of flagellated bacteria (Holwill and Burge, 1963; Chwang and Wu, 1971). For four bacterial specimens presently analysed, the experimental values of u/fF ranged from 0.5 to 0.9, whereas the theoretical values were about 0.3. As reported by the preceding paper, such a tendency for the experimental values to exceed the theoretical ones by two or three times was also seen in u/fB and, consequently, the experimental and the theoretical values of fF/fB showed good agreement. From the results of these quantitative analyses of the movements of flagellated bacteria, it was concluded that the validity of the hydrodynamic model was further supported experimentally.","PeriodicalId":76011,"journal":{"name":"Journal of mechanochemistry & cell motility","volume":"3 3","pages":"185-93"},"PeriodicalIF":0.0,"publicationDate":"1976-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12115638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Heavy metals and spermatozoan motility. III conformational changes induced by divalent cations and by ATP in flagellar proteins. 重金属与精子活力。鞭毛蛋白中二价阳离子和ATP诱导的构象变化。

Journal of mechanochemistry & cell motility Pub Date : 1976-01-01

M Morisawa

引用次数: 0

On the structure of steadily propagating rings of chemotactic bacteria. 趋化细菌稳定繁殖环的结构研究。

Journal of mechanochemistry & cell motility Pub Date : 1976-01-01

G Rosen, S Baloga

引用次数: 0

Preparation and characterization of fluorescent N-(3-pyrene)maleimide adducts of myosin. 肌球蛋白荧光N-(3-芘)马来酰亚胺加合物的制备与表征。

Journal of mechanochemistry & cell motility Pub Date : 1976-01-01

R P Liburdy, J K Weltman

引用次数: 0

The chemo-mechanical coupling relation in the oscillatory contraction-relaxation cycles of insect fibrillar muscle. 昆虫纤维肌收缩-松弛振荡周期中的化学-力学耦合关系。

Journal of mechanochemistry & cell motility Pub Date : 1976-01-01

R A Chaplain, B Frommelt, B Honka

{"title":"The chemo-mechanical coupling relation in the oscillatory contraction-relaxation cycles of insect fibrillar muscle.","authors":"R A Chaplain, B Frommelt, B Honka","doi":"","DOIUrl":"","url":null,"abstract":"The mechanical properties and the activity of the myofibrillar ATPase have been investigated at 21 degrees C on glycerinated back muscle from the water-bug Lethocerus colossicus. When the fibres were held under isometric conditions after stretching them by 0.5--4%, the ATPase required to maintain a given tension increases from 19 to 39 p-moles ATP split for each mg of tension developed as the Ca2+ level is increased from 10(-7) to up to 10(-5) M. The mechanical properties and the ATPase activity have been determined for Ca2+-activated fibres using sinusoidal frequencies of 1--30 HZ and oscillatory amplitudes of 0.5--6% peak-to-peak. In this way the R.M.S. velocity of sinusoidal movement was varied between 0.1-10 mm/sec. The rate of ATP splitting associated with oscillatory tension development, the dynamic tension cost, increases both with Ca2+ and with frequency of oscillation (at 1% peak-to-peak amplitude), becoming as high as four times the isometric value. The oscillatory power output which can be obtained is increased when the Ca2+ level is raised from 10(-7) to 10(-5) M or towards higher amplitudes of oscillation. The chemo-mechanical coupling efficiency increases proportionally with the R.M.S. velocity of muscle movement. In presence of 10(-5) M Ca2+ optimal efficiencies of 5.5--6.2 kcal work per mole ATP split are obtained at R.M.S. velocities of 1.3--2 muscle lengths/sec. The ability of the muscle fibres to perform osciillatory work at the higher frequencies was much reduced at lower Ca2+ levels of 10(-6) or 10(-7) M and the maximal efficiencies never exceeded 2.2 kcal/mole.","PeriodicalId":76011,"journal":{"name":"Journal of mechanochemistry & cell motility","volume":"3 4","pages":"253-64"},"PeriodicalIF":0.0,"publicationDate":"1976-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"11359609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Motility evaluation of bull spermatozoa by photon correlation spectroscopy. 光子相关光谱法评价公牛精子活力。

Journal of mechanochemistry & cell motility Pub Date : 1976-01-01

D F Cooke, F R Hallett, C A Barker

引用次数: 0