ライフサイエンスコーパス: crossbridge

1 with the structural "backbone" of the myosin crossbridge.

2 to index the lifetime of the prerigor, AMADP crossbridge.

3 ioether linkages in addition to the cofactor crossbridge.

4 to the compliance known to be present in the crossbridge.

5 he amino group of the pentaglycine cell wall crossbridge.

6 ing the aggregate number of force-generating crossbridges.

7 results from rotation of actin-bound myosin crossbridges.

8 ggesting that it arose from actively cycling crossbridges.

9 of ATP, enough only for a single turnover of crossbridges.

10 reonine (T) and the amino group of cell-wall crossbridges.

11 y affects the number of attached and cycling crossbridges.

12 e used by SR-Ca2+ pumps and the remainder by crossbridges.

13 promote strong binding of endogenous myosin crossbridges.

14 o reductions in the number of strong-binding crossbridges.

15 ridges, and decreased the flexibility of the crossbridges.

16 dent on feedback effects of force-generating crossbridges.

17 to some extent, with that of cycling myosin crossbridges.

18 hat rear bridges are more strained than lead crossbridges.

19 realignment to fit into both types of rigor crossbridges.

20 f myofilaments powered by the cycling myosin crossbridges.

21 ow double-headed lead and single-headed rear crossbridges.

22 have a nonhelical, side-polar arrangement of crossbridges.

23 tachment kinetics at the level of individual crossbridges.

24 nd exposes a tethering segment of S2 in many crossbridges.

25 ting in cooperative binding of other cycling crossbridges.

26 de-linked to the amino group of pentaglycine crossbridges.

27 on is primarily determined by strong cycling crossbridges.

28 ted using a five-step kinetic scheme for the crossbridge/A-MATPase cycle where the force generating c

29 in skinned fibres by reducing the number of crossbridges able to productively bind to the thin filam

30 e, may serve as a swing-out adapter allowing crossbridge access to actin, as the elastic component of

31 In this work, we present the viscoelastic-crossbridge active-titin (VEXAT) model that can replicat

32 ight into the modulation mechanism of strong crossbridge and cTnI phosphorylation in cardiac thin fil

33 access to actin, as the elastic component of crossbridges and as part of a phosphorylation-regulated

34 -MHC-containing filaments did not extend the crossbridges and did not alter degree of order or flexib

35 echanisms: having a small number of attached crossbridges and probably utilizing intracellular Ca2+ b

36 ), as well more complex interactions between crossbridges and regulatory units (XB-RU interactions).

37 , leading to increased recruitment of myosin crossbridges and subsequent thin filament activation at

38 consists of paired rigor-like and non-rigor crossbridges and suggests possible transitions in the my

39 rises from increasing strain of all attached crossbridges and that the first transition reflects the

40 activated filaments requires strongly bound crossbridges, and (3) that crossbridges are bound to the

41 tation, increased the degree of order of the crossbridges, and decreased the flexibility of the cross

42 that do not average the repeating motifs of crossbridges, and thereby retain information on variabil

43 ch of six fn3 domains, and that the last two crossbridges are at the level of the first two groups of

44 ion of muscle and muscle fibres, most myosin crossbridges are attached to actin during isometric cont

45 es strongly bound crossbridges, and (3) that crossbridges are bound to the periphery of actin, at a s

46 verse lines in a portion of the A band where crossbridges are found (C zone).

47 tead, new non-rigor forms of variably angled crossbridges are found bound to actin sites not labeled

48 at in resting vascular smooth muscle, active crossbridges are inhibited by caldesmon.

49 In transverse view, AMPPNP "lead" crossbridges are less azimuthally bent than rigor.

50 This suggests that many crossbridges are weakly attached to actin, possibly at t

51 ising from radial forces exerted by attached crossbridges, are fast enough to occur during the power

52 ructure and argue against a bipolar, helical crossbridge arrangement.

53 axing position on actin that inhibits myosin-crossbridge association.

54 trained, relaxing position to inhibit myosin-crossbridge association.

55 order meridional reflection from the myosin crossbridges, at 14.56 nm) at each of a number of quick

56 mp enhances an early step in the actomyosin (crossbridge) ATPase cycle before Pi-release.

57 that a T-jump promotes an early step in the crossbridge-ATPase cycle that generates force.

58 measure of changes in the numbers of myosin crossbridges attached to actin during Ca2+ activation.

59 -dependent changes are independent of strong crossbridge attachment and likely arise from alterations

60 itch locomotory fibers, but surprisingly the crossbridge attachment rate has remained unchanged.

61 ve neighbor interactions or length-dependent crossbridge attachment, contributed unique features to t

62 These kinetics result in very few crossbridges being attached during contraction of superf

63 The role of dityrosine as a fluorescent crossbridge between adjacent calmodulin molecules within

64 single microtubules, but forms well-defined crossbridges between antiparallel filaments.

65 otic flagella the dynein motor proteins form crossbridges between the outer doublet microtubules.

66 The structure reveals flexible crossbridges between the two protofilaments, and subunit

67 structuring of axoplasm through intra-axonal crossbridging between adjacent neurofilaments or to othe

68 dergo dynamic rearrangement concomitant with crossbridge binding in the A band.

69 tivation and relaxation rates of tropomyosin/crossbridge binding kinetics differ most significantly b

70 ng to the thin filaments recruits additional crossbridge binding to actin as well as increased Ca2+ b

71 Our results also predicted crossbridge binding to be slowest in human and fastest i

72 highly cooperative process in which initial crossbridge binding to the thin filaments recruits addit

73 thought to involve switch-like regulation of crossbridge binding to the thin filaments.

74 Crossbridge binding, state transitions, and force in act

75 Another class of glycol-PNP crossbridge binds outside the rigor actin target zone.

76 very oxygen consumption in the presence of a crossbridge blocker, N-benzyl-p-toluene sulphonamide (BT

77 put is mediated by alterations in numbers of crossbridges bound to the thin filament.

78 to aggregate and the filaments are maximally crossbridged by fascin.

79 romotes formation of assemblies of oligomers crossbridged by zinc.

80 echanics and kinetics at the level of single crossbridges can contribute to increased cardiac contrac

81 under cellular conditions, unphosphorylated crossbridges can slowly cycle.

82 NP-N that becomes rigidified 1,000-fold upon crossbridging CENP-A and its adjacent nucleosomal DNA.

83 econstruction of AMPPNP fibers show only one crossbridge class, in the position of the rigor lead bri

84 The portion of the crossbridge close to the thick filament appears broader

85 Our findings suggest that at least 62% of crossbridge compliance is associated with the tail domai

86 dence of the peak tension suggest that a non-crossbridge component increasingly develops tension thro

87 In order to visualize the changes in crossbridge conformation and distribution that give rise

88 Crossbridges consist of the globular N-terminal catalyti

89 filament-associated protein localized to the crossbridge-containing C zones of striated muscle sarcom

90 To determine the fraction of crossbridges contributing to tension and the structural

91 sion rise is reduced to 30-40%, the peak non-crossbridge contribution and the residual force enhancem

92 ion is reduced to approximately 15%, and the crossbridge contribution to stretch-induced tension rise

93 nd some single-headed "lead" bridges but few crossbridges corresponding to the rear bridges of rigor.

94 rther study, physiological regulation of the crossbridge cycle by calponin.

95 The findings aid our understanding of the crossbridge cycle by showing that it may not be necessar

96 investigate the regulation of the actomyosin crossbridge cycle in cardiac muscles, the effects of ATP

97 ously developed mechano-kinetic model of the crossbridge cycle in frog muscle to simulate the tempera

98 Thereafter, the crossbridge cycle is largely truncated, with prepower st

99 herefore, the effect of CP on the actomyosin crossbridge cycle is proposed to occur through a functio

100 In contrast, when crossbridge cycle kinetics were slowed by lowering [ATP]

101 this may be due, at least in part, to faster crossbridge cycle kinetics.

102 tes, in part, by speeding the step(s) in the crossbridge cycle that limit loaded shortening rates, an

103 To investigate the kinetic parameters of the crossbridge cycle that regulate force and shortening in

104 Two processes characterize intermediate crossbridge cycle transitions, B (work producing) and C

105 d that the tension-generating step(s) in the crossbridge cycle was highly endothermic and was therefo

106 urrent models for the Ca2+ activation of the crossbridge cycle, but these models do not explain the s

107 an extra step in the attached pathway of the crossbridge cycle, perhaps located on a parallel pathway

108 ase perturb different molecular steps in the crossbridge cycle.

109 yosin binding site, at an early stage of the crossbridge cycle.

110 uring the prepowerstroke state of the dynein crossbridge cycle.

111 a full understanding of the operation of the crossbridge cycle.

112 s cardiac function by increasing the rate of crossbridge cycling and Ca[Formula: see text] transient

113 hat causes actin filaments, and hence myosin-crossbridge cycling and contraction, to switch on and of

114 Da myosin light chain (MLC), which activates crossbridge cycling and the polymerization of a pool of

115 with DCM and disrupts kinetics of Ca(2+) and crossbridge cycling by abolishing the myofilament respon

116 is indicates that dATP increased the rate of crossbridge cycling in cardiac muscle.

117 ry determinant in controlling the actomyosin crossbridge cycling kinetics of cardiac muscles, because

118 Crossbridge cycling kinetics were studied by measuring k

119 including thin filament on-off kinetics and crossbridge cycling kinetics with interactions within an

120 ed in silico modeling to further investigate crossbridge cycling kinetics.

121 tretch activation response are indicators of crossbridge cycling kinetics.

122 d phosphorylation also accelerated isometric crossbridge cycling kinetics.

123 This steric effect controls myosin-crossbridge cycling on actin that drives contraction.

124 n by C-protein is mediated by the effects of crossbridge cycling on the Ca2+ affinity of troponin C.

125 intrinsic length component increases loaded crossbridge cycling rates at short SL and beta-MyHC myoc

126 stent with contraction cost being minimized (crossbridge cycling), in contrast to the contractile cos

127 n important parameter in setting the rate of crossbridge cycling, and (2) C protein-mediated control

128 0 kDa light chain of myosin, which activates crossbridge cycling, as well as the polymerization of a

129 eases the pool of myosin heads available for crossbridge cycling, increasing steady-state force devel

130 tified substance(s) that inhibits myocardial crossbridge cycling, independent of Ca2+ or other second

131 ATPase activity by modifying the kinetics of crossbridge cycling.

132 ing a tropomyosin conformation that prevents crossbridge cycling.

133 tion, resulting in release of the "brake" on crossbridge cycling.

134 sed, redeveloped force, demonstrating active crossbridge cycling; strips containing normal h-caldesmo

135 t spatially explicit model to include radial crossbridge dependence which can produce mechanical func

136 ge force generation and faster (post-stroke) crossbridge detachment by negative strain.

137 tation that the Ca(2+)-dissociation rate and crossbridge detachment rate are similar in fast-twitch s

138 f Ca(2+) from troponin C (TnC) and decreased crossbridge detachment rate on the time course of relaxa

139 bladder fibers have evolved a 10-fold faster crossbridge detachment rate than fast-twitch locomotory

140 and very fast calcium transient, (ii) a fast crossbridge detachment rate, and (iii) probably a fast k

141 hat does not alter the rate-limiting step of crossbridge detachment.

142 and regulatory domains of the new non-rigor crossbridges differ from those in the atomic model of ac

143 )) and of force redevelopment after forcible crossbridge dissociation (k(act)) were similar and were

144 Calcium- and copper-crossbridged domains of synthetic block copolymers or na

145 ed state resulting in an increased number of crossbridges during Ca(2+) activation.

146 g sites on actin, thereby controlling myosin crossbridge dynamics and consequently muscle contraction

147 (2+) binding at neighbouring Tn sites and/or crossbridge feedback effects on Ca(2+) binding affinity.

148 hanged the myofilament characteristics via a crossbridge feedback mechanism.

149 These results suggest that (1) crossbridge flexibility is an important parameter in set

150 stroke size and stiffness of the "AM rigor" crossbridge for both myosins were comparable.

151 locity is increased, probably enhancement of crossbridge force generation and faster (post-stroke) cr

152 was to investigate the strain sensitivity of crossbridge force generation in muscle.

153 a characteristic rise in force showing that crossbridge force generation is endothermic (heat absorb

154 Thus the crossbridge force generation step in muscle is both temp

155 dial force-frequency relation, and increased crossbridge force-time integral (FTI).

156 structural changes are further modulated by crossbridge formation and fine-tuned by phosphorylation

157 re, Tmods are novel regulators of actomyosin crossbridge formation and muscle contractility, and futu

158 sitivity and cooperativity of force-inducing crossbridge formation between actin and myosin filaments

159 Enhanced actomyosin crossbridge formation caused by sarcomeric mutations in

160 ation, thin filament lengths, and actomyosin crossbridge formation in skeletal muscle fibers.

161 By mitigating enhanced actomyosin crossbridge formation through either genetic or pharmaco

162 s critical to the inhibition of actin-myosin crossbridge formation when intracellular calcium is low.

163 n actin polymerization, fimbrin binding, and crossbridge formation, presumably achieved by a feedback

164 X-ray diagrams, suggesting that the average crossbridge forms in the reconstruction reflect the nati

165 force is associated with a transition of the crossbridges from a state in which they are nonspecifica

166 f C protein by protein kinase A extended the crossbridges from the backbone of the filament, changed

167 nism for the previously observed increase in crossbridge FTI.

168 idal length perturbation analysis to compare crossbridge function in skinned left ventricular (LV) ep

169 lament is important for the formation of the crossbridge gap and thus the termination of the thick fi

170 dition, although 3-D visualization of myosin crossbridges has been possible in rigor, it has been dif

171 ontact interface with actin, while nontarget crossbridges have variable contact interfaces.

172 ion with a high-affinity toxin or disulphide crossbridge impedes the return of this voltage sensor to

173 Similar comparison using lead-type crossbridges in AMPPNP reveals departures from the rigor

174 The structure and function of myosin crossbridges in asynchronous insect flight muscle (IFM)

175 eflections generated by the arrays of myosin crossbridges in contracting muscle.

176 he possible roles of strongly binding myosin crossbridges in determining loaded shortening and power

177 Crossbridges in filaments with beta-MHC were less ordere

178 ure of chicken subfragment 1 (S1) to fit IFM crossbridges in lower-resolution electron microscopy tom

179 ed the three-dimensional structure of myosin crossbridges in situ in order to define the structural c

180 phosphorylation-regulated on-off switch for crossbridges in smooth muscle.

181 sphate (Pi) should shift the distribution of crossbridges in the actomyosin ATPase (AMATPase) to incr

182 In contrast to the rigor lead and rear crossbridges in the double chevrons, the averaged recons

183 hus reducing both the fraction of actomyosin crossbridges in the strongly bound state (-29%) and fibe

184 Comparison of in situ crossbridges in tomograms of rigor with atomic model of

185 Rather, it may be related to a decrease in crossbridge-induced activation of the thin filament at t

186 The relative flexibility of the crossbridges inferred from the optical diffraction patte

187 erties (M80Q sTnCF27W) did not affect strong crossbridge inhibition by 2,3-butanedione monoxime when

188 Effects of temperature, crossbridge inhibition, or variation in [MgATP] support

189 Muscle force is generated by myosin crossbridges interacting with actin.

190 uctural and kinetic effects of Ca2+ binding, crossbridge interaction, and protein kinase A phosphoryl

191 to an inhibitory position that blocks myosin-crossbridge interaction.

192 Acto-myosin (crossbridge) interaction was either inhibited using N-be

193 est known vertebrate muscle, we examined the crossbridge kinetic rates responsible for high contracti

194 , PKA phosphorylation of cMyBP-C accelerates crossbridge kinetics and loss of this regulation leads t

195 e show that cleavage leads to alterations in crossbridge kinetics and passive structural signatures o

196 demonstrate that to achieve rapid actomyosin crossbridge kinetics bat and songbird SFM express myosin

197 al modeling showed that this variant affects crossbridge kinetics by decreasing both Ca(2+) k(OFF)-ra

198 Decreasing the rate of crossbridge kinetics by reducing intracellular inorganic

199 lel studies with intact muscles, we assessed crossbridge kinetics indirectly by determining f(min) (t

200 We examined the influences of Ca2+ and crossbridge kinetics on the maximum rate of force develo

201 loaded shortening velocity via regulation of crossbridge kinetics or crossbridge number, the shorteni

202 at the maximum relaxation rate is limited by crossbridge kinetics rather than by k(off).

203 yosin binding protein (cMyBP)-C may regulate crossbridge kinetics to modulate contraction.

204 Steady-state isometric force and crossbridge kinetics were measured before and after PKA

205 Further, normal crossbridge kinetics were observed, demonstrating that m

206 e N-terminal domain in regulating actomyosin crossbridge kinetics, in particular with respect to the

207 may be mainly due to species differences in crossbridge kinetics.

208 ller myofilament lattice spacing, and slower crossbridge kinetics.

209 ings are consistent with a lack of effect on crossbridge kinetics.

210 one in which stereospecifically bound myosin crossbridges label the actin helix.

211 tomograms of "glycol-stiff" sarcomeres show crossbridges large enough to contain only a single myosi

212 g to the enhanced ADP release rates from the crossbridge, likely responsible for the observed differe

213 Crossbridge links between the central microtubule pair h

214 d control of the position and flexibility of crossbridges may regulate actomyosin ATPase activity by

215 phase during which ATP molecules soften the crossbridge-microtubule attachment at the cilium inflect

216 A new crossbridge motif identified in AMPPNP-treated muscle co

217 se in birefringence has been correlated with crossbridge movement away from the thick filaments.

218 birefringence response inverted, suggesting crossbridge movement similar to that of skeletal muscle.

219 Our data demonstrate that the gap of myosin crossbridges near the end of the thick filament closely

220 ty via regulation of crossbridge kinetics or crossbridge number, the shortening velocity was measured

221 at cleaves the stem peptide and pentaglycine crossbridge of the cell wall and alters processing and a

222 d that the ATPase domain of myosin forms the crossbridges of thick filaments that bind actin, and int

223 tion of cTnI were similar to those of strong crossbridges on structural changes in cTnI.

224 he docking sites for weak and strongly bound crossbridges on thin filaments.

225 kbones and, in addition, reveal projections (crossbridges) on only two opposite sides of the square.

226 is determined primarily by strongly binding crossbridges or by [Ca(2+)] per se, which was done by me

227 Although bipolar tetramers were known to crossbridge pairs of microtubules, the mechanism for org

228 These results indicate that strongly binding crossbridges play a significant role in determining load

229 Divalent cations are shown here to crossbridge polyanionic amphiphiles, which thereby demix

230 bundles, time-dependent use of at least two crossbridging proteins, filament turnover, treadmilling,

231 (1,0)) indicate that PKA treatment increased crossbridge proximity to thin filaments under all condit

232 e is largely truncated, with prepower stroke crossbridges rapidly detaching at high strain and attach

233 nction myocytes, indicating less myosin in a crossbridge-ready disordered-relaxed (DRX) state.

234 hin filament binding sites (cTnI) or altered crossbridge recruitment (cMyBP-C/titin).

235 The ATP usage per twitch by the myosin crossbridges remains essentially constant at approximate

236 Correspondence analysis of 1831 38.7 nm crossbridge repeats grouped self-similar forms from whic

237 orescence originating from approximately 400 crossbridges residing in a small volume defined by a con

238 t with the strong binding of a single-myosin crossbridge, resulting in cooperative binding of other c

239 of actomyosin subfragment 1 to the averaged crossbridges shows that the detectable differences betwe

240 ) to increase the relative population of the crossbridge state prior to ADP release and Pi release, r

241 increases with temperature because attached crossbridge states bearing a relatively low force conver

242 thereby retain information on variability of crossbridge structure and distribution.

243 he rate of ADP release from the actin-myosin crossbridge (the step that limits contraction velocity).

244 there is coupling between the RU and myosin crossbridges, the functional outcome of cardiomyopathy-r

245 t counterion entropy dominates electrostatic crossbridges, thus illustrating the insights gained into

246 position on the thin filament and binding of crossbridges to actin.

247 flight muscle the response of in situ rigor crossbridges to AMPPNP binding is not uniform.

248 the important contribution of strong binding crossbridges to cardiac muscle activation, likely mediat

249 romised, the relative contribution of strong crossbridges to maintain thin filament activation is inc

250 iated by cooperative recruitment of adjacent crossbridges to maximize force redevelopment against ext

251 ggest that myofibrillar-space calcium causes crossbridges to move away from the thick filaments witho

252 identically correlated, which indicated that crossbridge turnover was unaffected by Tm isoform switch

253 ion and the structural changes that attached crossbridges undergo when generating force, we monitored

254 e activation or the relative contribution of crossbridges versus Ca2+ to thin filament activation.

255 cing (b) and work-absorbing (c) steps of the crossbridge were less in alphaMHC403/+ strips than in wi

256 In thick filaments with alpha-MHC, crossbridges were clearly visible.

257 P utilization rates of the SR-Ca2+ pumps and crossbridges were measured using a coupled assay system

258 ve proportions used by SR-Ca2+ pumps and the crossbridges were similar to other muscles.

259 The crossbridges were synchronized by rapid photogeneration

260 scles and observed by negative staining show crossbridges with a 14.5-nm repeat projecting in opposit

261 probability of strong interactions of myosin crossbridges with actin, thereby decreasing cooperative

262 Crossbridges with an average 90 degrees axial angle cont

263 ant allosteric effects on the interaction of crossbridges with the thin filament.

264 the amino group of the m-diaminopimelic acid crossbridge within the listerial peptidoglycan.

265 ermit simultaneous examination of all myosin crossbridges within the unit cell and direct comparison

266 al link influenced the kinetics of activated crossbridges without affecting the aggregate number of f

267 butable to the reduced frequency b, at which crossbridge work is maximum.

268 tively, Ca2+ control of the number of active crossbridges would yield similar velocity-tension relati

269 Tm(H276N) slowed crossbridge (XB) detachment rate (g) by 19%.

270 The magnitude of length-mediated increase in crossbridge (XB) recruitment (E0) decreased by ~33% and

271 nI modulate muscle length-mediated effect on crossbridge (XB) recruitment dynamics, Ca(2+)-activated

272 ns between regulatory units (RU-RU), between crossbridges (XB-XB), as well more complex interactions