Abstract：
:Numerous biological processes, including muscular contraction, depend upon the mechanical properties of actin filaments. One such property is resistance to bending (flexural rigidity, EI). To estimate EI, we attached the ends of fluorescently labelled actin filaments to two microsphere 'handles' captured in independent laser traps. The positions of the traps were manipulated to apply a range of tensions (0-8 pN) to the filaments via the microsphere handles. With increasing filament tension, the displacement of the microspheres was inconsistent with a microsphere-filament system that is rigid. We maintain that this inconsistency is due to the microspheres rotating in the trap and the filaments bending near either attachments to accommodate this rotation. Fitting the experimental data to a simple model of this phenomena, we estimate actin's EI to be approximately 15 x 10(3) pNnm2, a value within the range of previously reported results, albeit using a novel method. These results both: support the idea that actin filaments are more compliant than historically assumed; and, indicate that without appropriately pretensioning the actin filament in similar laser traps, measurements of unitary molecular events (e.g. myosin displacement) may be significantly underestimated.
journal_name
J Muscle Res Cell Motiljournal_title
Journal of muscle research and cell motilityauthors
Dupuis DE,Guilford WH,Wu J,Warshaw DMdoi
10.1023/a:1018672631256subject
Has Abstractpub_date
1997-02-01 00:00:00pages
17-30issue
1eissn
0142-4319issn
1573-2657journal_volume
18pub_type
杂志文章abstract：:There is evidence to suggest that 8 nm calcium transport particles in the sarcoplasmic reticulum are involved in the regulation of twitch properties in adult muscles. We have studied ultrastructural characteristics of the sarcoplasmic reticulum in relation to previously defined physiological changes that take place in...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1007/BF01753413
更新日期：1986-04-01 00:00:00
abstract：:The kinetics of smooth muscle are thought to be partially determined by the level of the expression of the 7 amino acid insert, SMB, in the myosin heavy chain, as SMB is generally expressed at higher levels in faster smooth muscle. In this study, we determined the role of this insert on shortening velocity and force r...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1023/b:jure.0000035879.87045.4b
更新日期：2004-01-01 00:00:00
abstract：:Five monoclonal antibodies that react with different regions of myosin light chain 1 from human ventricular myocardial muscle were used to obtain information on interactions between the light chain 1 and heavy chains and generally on the tertiary structure of the light chain 1 within the myosin head. We performed West...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1007/BF01766461
更新日期：1992-06-01 00:00:00
abstract：:The pattern of expression of different types of myosin heavy chains and the development of different generations of muscle cells during foetal life were studied in four bovine muscles with widely varying characteristics, the Masseter, Longissimus thoracis, Cutaneus trunci and Diaphragma. Different complementary techni...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1007/BF00122120
更新日期：1994-08-01 00:00:00
abstract：:MagFluo-4 fluorescence (Ca2+) transients associated with action potentials were measured in intact muscle fibres, manually dissected from toads ( Leptodactylus insularis ) or enzymatically dissociated from mice. In toads, the decay phase of the Ca2+ transients is described by a single exponential with a time constant ...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1007/s10974-004-4071-z
更新日期：2004-01-01 00:00:00
abstract：:Using a variety of techniques, we have demonstrated the presence of at least two fibre types in Limulus median telson levator muscle. By light and electron microscopy, large (2,156 microns 2 mean cross-sectional area) fibres have A-bands of 4.1 microns, one-half I bands of 2.15 microns and Z lines less than or equal t...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1007/BF01739856
更新日期：1989-02-01 00:00:00
abstract：:In Drosophila melanogaster two high molecular weight tropomyosin isoforms, historically named heavy troponins (TnH-33 and TnH-34), are encoded by the Tm1 tropomyosin gene. They are specifically expressed in the indirect flight muscles (IFM). Their N-termini are conventional and complete tropomyosin sequences, but thei...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1007/s10974-005-9044-3
更新日期：2006-01-01 00:00:00
abstract：:Myosin heavy chain species were investigated during development in avian pectoralis major muscles (type IIB fibres) by high resolution anion-exchange chromatography of the myosin head region, subfragment-1. At 15 days in ovo four distinct fast-type heavy chain species, I, II, III and IV, in order of elution, were iden...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1007/BF01745118
更新日期：1991-06-01 00:00:00
abstract：:We found that the active tension of C2C12 myotubes that had been subjected to artificial exercise for ~10 days decreased rapidly after termination of the artificial exercise. When differentiated C2C12 myotubes were subjected to continuous 1 Hz artificial exercise for ~10 days, the active tension increased to ~4× compa...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1007/s10974-010-9230-9
更新日期：2010-12-01 00:00:00
abstract：:Hodges and his colleagues identified a 12 amino acid fragment of troponin I (TnI-ip) that inhibits Ca(2+)-activated force and reduces the effectiveness Ca(2+) as an activator. To understand the role of troponin C (TnC) in the extended cooperative interactions of thin filament activation, we compared the effect of TnI-...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1007/s10974-013-9336-y
更新日期：2013-05-01 00:00:00
abstract：:The effects of two amino acids, arginine which has a positively charged side-chain and glutamate which has a negatively charged side-chain on the Ca2+-activation properties of the contractile apparatus were examined in four structurally and functionally different types of skeletal muscle; long- and short-sarcomere fib...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1007/s10974-004-2769-6
更新日期：2004-01-01 00:00:00
abstract：:Heart disease is a leading cause of death in patients with Duchenne muscular dystrophy (DMD). Patients with DMD lack the protein dystrophin, which is widely expressed in striated muscle. In skeletal muscle, the loss of dystrophin results in dramatically decreased expression of the dystrophin associated glycoprotein co...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1007/s10974-013-9362-9
更新日期：2013-12-01 00:00:00
abstract：:The remodelling of connective tissue components is a fundamental requirement for a number of pivotal processes in cell biology. These may include myoblast migration and fusion during development and regeneration. In other systems, similar biological processes are facilitated by secretion of the matrix metalloproteinas...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1023/a:1005670507906
更新日期：2000-04-01 00:00:00
abstract：:Telokin, a 17 kDa smooth muscle specific protein, consists of the C-terminal domain of MLCK, is phosphorylated by PKA and PKG at Ser13 in vivo (Wu et al. (1998) J Biol Chem 273: 11362-11369; Walker et al. (2001) J. Biol Chem 276: 24519-24524) and is proposed to induce Ca2+-desensitization through activation of myosin ...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1007/s10974-004-7807-x
更新日期：2004-01-01 00:00:00
abstract：:The pattern of spontaneous skeletal muscle degeneration and clinical recovery hindlimb muscles of the mdx mutant mouse was examined for functional and metabolic confirmation of apparent structural regeneration. The contractile properties, histochemical staining and myosin light chain and parvalbumin contents of extens...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1007/BF01738755
更新日期：1988-12-01 00:00:00
abstract：:The details of the global and local structure and function of titin, a giant filamentous intrasarcomeric protein are largely undiscovered. Here we discuss a combination of bulk-solution and novel single-molecule techniques that may lend unique insights into titin's molecular dynamic, structural and mechanical characte...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章,评审
doi：10.1023/a:1023414624092
更新日期：2002-01-01 00:00:00
abstract：:The mRNA levels of the adult and the neonatal sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPases (SERCA1a and SERCA1b, respectively) and those of the muscle regulatory factors (MRFs: myoD, myf-5, myogenin, MRF4) have been assessed by RT PCR in rat soleus muscles immobilized for 3 days in an extended position (passive s...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1023/a:1005541522599
更新日期：1999-05-01 00:00:00
abstract：:The optimal utilization of energy substrates in muscle fibers is of primary importance for muscle contraction and whole body physiology. This study aimed to investigate the age-related changes in some indicators of glucose catabolism and fatty acid oxidation in muscles of growing rabbits. Longissimus lumborum (fast-tw...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1007/s10974-004-2768-7
更新日期：2004-01-01 00:00:00
abstract：:A method for quick-freezing muscles while observing their mechanical properties until the moment of freezing is described. This method was used to freeze the anterior byssus retractor muscle (ABRM) of Mytilus edulis. Intact muscle in the presence of sucrose as a cryoprotectant was freeze-substituted in acetone, fixed ...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1007/BF01758426
更新日期：1989-08-01 00:00:00
abstract：:Skeletal muscle myofibers constantly undergo degeneration and regeneration. Histopathological features of 6 skeletal muscles (cranial tibial [CT], gastrocnemius, quadriceps femoris, triceps brachii [TB], lumbar longissimus muscles, and costal part of the diaphragm [CPD]) were compared using C57BL/10ScSn-Dmd mdx (mdx) ...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1007/s10974-016-9452-6
更新日期：2016-10-01 00:00:00
abstract：:This paper studies human gallbladder (GB) smooth muscle contractions. A two-state cross-bridge model was used to estimate the apparent attachment and detachment rate constants, as well as increased Ca2+ concentration from the peak active stress during the isometric contraction. The active stress was computed from a me...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1007/s10974-011-9260-y
更新日期：2011-11-01 00:00:00
abstract：:In isolated myosin the reaction sequence of essential thiol groups with N-ethylmaleimide was studied using the following five approaches: kinetics of the modification reaction, effects of modification on enzyme properties, affinity chromatography of isolated subfragment-1 stemming from modified myosin, isolation of cy...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1007/BF00711923
更新日期：1980-03-01 00:00:00
abstract：:Skeletal muscle hypertrophy is a result of increased load, such as functional and stretch-overload. Activation of satellite cells and proliferation, differentiation and fusion are required for hypertrophy of overloaded skeletal muscles. On the contrary, a dramatic loss of skeletal muscle mass determines atrophy settin...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章,评审
doi：10.1007/s10974-010-9204-y
更新日期：2009-12-01 00:00:00
abstract：:A high resolution, time efficient method is described for determining the complex modulus of activated striated muscle. In this method the applied oscillation of muscle length takes the form of pseudo-random binary noise, PRBN. As a time-domain signal, PRBN is an extension of the double step approach to include n step...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1007/BF01753650
更新日期：1986-08-01 00:00:00
abstract：:The effects of 2,3-butanedione monoxime (BDM) on contraction characteristics were studied at 5 degrees C in single intact fibres isolated from the tibialis anterior muscle of the frog. The force-velocity relation was determined using the controlled-velocity method in either whole fibres or short fibre segments in whic...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1007/BF01737994
更新日期：1992-10-01 00:00:00
abstract：:The present study describes transitions in myosin heavy chain expression in the extraocular muscles of rats between the ages of E17 and adult. The unique phenotype of the extraocular muscle is reflected in its fibre type composition, which is comprised by six distinct profiles, each defined by location (orbital versus...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1007/BF00240928
更新日期：1996-06-01 00:00:00
abstract：:Gaps in our understanding of muscle mechanics demonstrate that the current model is incomplete. Increasingly, it appears that a role for titin in active muscle contraction might help to fill these gaps. While such a role for titin is increasingly accepted, the underlying molecular mechanisms remain unclear. The goals ...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1007/s10974-019-09540-y
更新日期：2020-03-01 00:00:00
abstract：:Previous studies have shown that lengthening contractions, in contrast to isometric contractions, readily result in sustained malfunctioning of the exercised muscles. The present study was performed to investigate whether an exercise period with many (240) lengthening contractions (LC) results in alterations in muscle...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1023/a:1005345603882
更新日期：1998-05-01 00:00:00
abstract：:Critical illness myopathy (CIM) is associated with severe muscle atrophy and fatigue in affected patients. Apoptotic signaling is involved in atrophy and is elevated in muscles from patients with CIM. In this study we investigated underlying mechanisms of apoptosis-related pathways in muscles with different fiber type...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1007/s10974-015-9410-8
更新日期：2015-06-01 00:00:00
abstract：:Cardiac muscle M-band structures in several mammals (guinea pig, rabbit, rat and cow) and also from three teleosts (plaice, carp and roach), have been studied using electron microscopy and image processing. Axial structure seen in negatively stained isolated myofibrils or negatively stained cryo-sections shows the pre...
journal_title：Journal of muscle research and cell motility
pub_type： 杂志文章
doi：10.1007/BF00121071
更新日期：1994-12-01 00:00:00
