Nano molecular motors

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Publié par

larec

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Poids de l'ouvrage

1 Mo

Niveau: Supérieur, Master, Bac+4
Nano-6 molecular motors 1 Molecular motors I. Orders of magnitudes (mass, forces,etc..) II. Cytoskeleton (Actin, tubulin, keratin…) III. Energy sources (thermal, chemical); ATP hydrolysis IV. Myosin and deyein based motors (muscles, sperm) V. Mechanisms for molecukar motors

examples amino-acid

kt thermal

conformal change

chemical atp

molecular motors

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Publié par

larec

Nombre de lectures

Poids de l'ouvrage

1 Mo

Molecular motor

oMelucalromotsrI.Ordersofmagnitudes (mass, forces,etc..)II.Cytoskeleton(Actin, tubulin, keratin…)III.Energysources (thermal, chemical); ATP hydrolysisIV.Myosinanddeyeinbasedmotors(muscles, sperm)V.Mechanismsfor molecukarmotorsNano-6 molecular motors1

D 074ATP=AdenosinetriphosphateExamplesamino-acid~ 300-600 DExamplesaromaticring C6H126*12+12=84 DMass: Dalton ≡1 H atom≡1.673 10-27kgOrdersofmagnitudesATP=ADP+Pphosphatetinua2r 5m oktoTrsProtein100 kDSize6-10 nmVolume 120 nm3snietorp 0001-0001nitca(erutcurtsxelpmoc eroMsdica-onima 0005-0052lucelom 6-onaN

evo)noitarelecca(ecroflaitrenielttil59-ytivarg oNsecrofWdV ybg10-6pNn01iNpdmagneticnelasticiViscousbthermalVan der slaaWgravitynkT=4.1410-21J4pN.1nmo1-50 pNi1-1000pNt10-100pN1-1000pNoC-OH10pNNano-6 molecular motorsmcovalentd3eForces in biologypmadr

!A50.0 ni spotss/mμ52=vsn 51=τmn/Np4=κD501=gk22-01 7.1=mm/s.Np06=γD501=gk22-01 7.1=msn 002=τm/s.Nn02=γD2101 2=gk51-01 4=mmuiretcabselacsemit4elastic/viscousFvConformalchangeγ=τκvproteinFNano-6 molecular motorsproteinm=τγInertial/viscousτ=3 ps

0151τμLDs ni mn 01srevoCs/2mμ76=Dnietorp=DTkγTk 21=J02-01 5=mn.Np05MyosinnumbersElastic: conformalchange 5nmstiffness4pN/nmEel=1κδ2=2chemicalk4 T1 t0h-2e1rJmalNano-6 molecular motors5Energies52Tk ATP hydrolysis−−==⋅=282210176

slairetamlacigoloibfossenffitsdnaseitisneD)apG( Esuludom gnuoYCarbonnanotubeleetsplastickeratinnitcatubulin00310224.24.23.2.19vdWforces6cytoskeletonNano-6 molecular motorshemoglobin1.38Chromosome1.36Virus1.15Synapticvesicle1.05densitiestubulin: axons (neurons), spermflagellaactin: muscles,..Keratin: hairs, wool, nails, hoofs, horns,..

yCotksleteno-AActinfilaments (Φ=6nm)tcniUnit ellement(monomer)Two-strandtwistedfibersNano-6 molecular motorspolymer7

ntntnnAAAK][][][egral ndnartsitlumniworgylnonacsremylop gnoLtnemalifdednartsowtdnaenofonoitaziremyloP8typically1000twostrandnav≈K1[At]KKMultistrandgrowor shrinkattheendsNano-6 molecular motorsFor a single strand⎛⎞n[An]=Kexp⎜−⎟n⎝⎠0[At]=∑[An]=1n01yllacipyt1=∑=≈va

mm 6elubut-orciMmμ 51nitcAmn 05ANDhtgnelecnetsisreP=pLIETksremyloplacigoloibfognidneB9srotom ralucelom 6-onaNLπ4=Ir4κ=3E3ILy(L)F=κyIE3microtubule3EI=30 10-24Nm2L=10μmκ=10−7Nm0.1pN bendthetubule by y=1μmEffectofthermal fluctuation: persistencelength⎛⎞Lpcosθ(s)=exp⎜⎜−Ls⎟⎟⎝⎠ppolymer

yCotksleteno-utMicro-tubules(Φ=25nm)13 strandedfilament woundin a cylindricalstructureubilnNano-6 molecular motors01

ATP hydrolysisATP→ADP+PiTk52PDAThis reactionisusedfor•transition betweentwostate (motion)•Conformation change (springforce)Nano-6 molecular motors11

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