Nano molecular motors

Cnrs/Lcmi

Description

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


• atp


• kt thermal


• conformal change


• chemical atp


• molecular motors

Sujets

• Molecular motor

Informations

• Publié par: larec
• Nombre de lectures: 30
• Poids de l'ouvrage: 1 Mo

Extrait

oMelucalromotsr I.Ordersofmagnitudes (mass, forces,etc..) II.Cytoskeleton(Actin, tubulin, keratin…) III.Energysources (thermal, chemical); ATP hydrolysis IV.Myosinanddeyeinbasedmotors(muscles, sperm) V.Mechanismsfor molecukarmotors Nano-6 molecular motors1

D 074ATP=Adenosinetriphosphate Examplesamino-acid~ 300-600 D Examplesaromaticring C 6 H 12 6*12+12=84 D Mass: Dalton ≡1 H atom≡1.673 10-27kg Ordersofmagnitudes ATP=ADP+P phosphate tinu a 2 r 5 m   o k to T rs Protein 100 kD Size6-10 nm Volume 120 nm 3 snietorp 0001-0001nitca( erutcurtsxelpmoc eroM sdica-onima 0005-005 2lucelom 6-onaN

evo )noitarelecca( ecroflaitrenielttil 5 9- ytivarg oN secrof WdV ybg 10-6pN n 01 i Np d magnetic n elastic i Viscous b thermal Van der slaaW gravity n kT=4.1410-21J 4pN.1nm o 1-50 pN i 1-1000pN t 10-100pN 1-1000pN o C-OH10pN Nano-6 molecular motors m covalent d 3 e Forces in biology pmadr

!A50.0 ni spots s/mμ52=v sn 51=τ mn/Np4=κ D 5 01=gk 22- 01 7.1=m m/s.Np06=γ D 5 01=gk 22- 01 7.1=m sn 002=τ m/s.Nn02=γ D 21 01 2=gk 51- 01 4=m muiretcab selacsemit 4 elastic/viscous F v Conformalchange γ =τ κ v protein F Nano-6 molecular motors protein m =τ γ Inertial/viscous τ=3 ps

01 51 τμ L D s  ni mn 01srevoC s/2mμ76=Dnietorp = D Tk γ Tk 21=J02-01 5=mn.Np05 Myosinnumbers Elastic: conformalchange 5nm stiffness4pN/nm E el = 1 κδ 2 = 2 chemical k 4  T 1  t 0 h -2 e 1 r J mal Nano-6 molecular motors5 Energies 52Tk  ATP hydrolysis − − == ⋅ = 28 2 21 01 76

slairetamlacigoloibfossenffitsdnaseitisneD )apG( Esuludom gnuoY Carbon nanotube leets plastic keratin nitca tubulin 0031 022 4.2 4.2 3.2 .19 vdWforces 6 cytoskeleton Nano-6 molecular motors hemoglobin1.38 Chromosome1.36 Virus1.15 Synapticvesicle1.05 densities tubulin: axons (neurons), spermflagella actin: muscles,.. Keratin: hairs, wool, nails, hoofs, horns,..

yCotksleteno-A Actinfilaments (Φ=6nm) tcni Unit ellement(monomer) Two-strandtwistedfibers Nano-6 molecular motors polymer 7

n t n t nn A A A K ][ ][ ][ egral n dnartsitlum niworgylnonacsremylop gnoL tnemalifdednartsowtdnaenofonoitaziremyloP 8 typically1000 twostrand n av ≈ K 1 [ A t ] KK Multistrandgrowor shrinkattheends Nano-6 molecular motors For a single strand ⎛⎞ n [ A n ] = Kexp ⎜ − ⎟ n ⎝⎠ 0 [ A t ] = ∑ [ A n ] = 1n 01yllacipyt 1 = ∑ =≈ va

mm 6elubut-orciM mμ 51nitcA mn 05AND htgnel ecnetsisreP = p L IE Tk sremyloplacigoloibfognidneB 9srotom ralucelom 6-onaN L π 4 = Ir 4 κ= 3E 3 I L y(L) F =κ y IE3 microtubule 3EI=30 10-24Nm2 L=10μm κ= 10 − 7 Nm 0.1pN bendthetubule by y=1μm Effectofthermal fluctuation: persistencelength ⎛⎞ L p cos θ ( s ) = exp ⎜ ⎜ − L s ⎟ ⎟ ⎝⎠ p polymer

yCotksleteno-ut Micro-tubules(Φ=25nm) 13 strandedfilament woundin a cylindrical structure ubiln Nano-6 molecular motors01

ATP hydrolysis ATP→ADP+PiTk52 PDA This reactionisusedfor •transition betweentwostate (motion) •Conformation change (springforce) Nano-6 molecular motors11