Low frequency dielectric spectroscopy of biopolyelectrolytesInstitut za fziku Laboratory for biological physicsSilvia Tomi, Tomislav Vuleti, Sana !olanski "abi, Tomislav Ivek1 #otivationTomislav Vuleti, Institut za fiziku$roteins and !%& are or'anized moelcular mac(ines$(ysics of )self*or'anized molecular systems"iomacromolecules are polyelectrolytesInteractions and c(ar'e correlations in solution in+uence t(e orderin' and selfor'anization of biomacromolecules!ielectric spectroscopy may provide information on t(e structure and orderin' of t(e ensemble, as well as on conformation of sin'le molecules !ielectric function( ) [ ]( ) ) ( + = ) ( + =) ( =+ = ) ( 000 iE i jE Ddtt dDt E000) () ( ) () () ( t,conductivity andconductivity and dielectric function dielectric function, measured measured conductivity and dielectricconductivity and dielectric function functionTomislav Vuleti, Institut za fiziku0 0)+)= = + = = ) ( (__________ ' ' ') ( ) ( ________ (GSliCSlC i G Y YSl $recision impedance analyzer&'ilent -./-&0 -1 2z3441 #2z&'ilent"%5 connectors5onductivity c(amber 6or aqueous samples0 4783 .111S9cm: volume 813.11 L;eproducibility 0.5 m'9mL;an'e of studied concentrations0 1714 3 8 m'9mLSemidilute re'ime0 c I cH cH 3 crossover concentration=molecule mass 9 swept volumecH % mbp 9 %JaJ cH K 4 9 Lc. HcHK%3.Semidilute re'ime!ilute re'ime#odern t(eoretical approac(esTomislav Vuleti, Institut za fiziku 26 relaBation probes t(e structureof t(e w(ole biopolymer solutioncorrelation len't( or mes( size at crossover concentration0 c c* Lc = Na&way from cH , s(ould depend on c0 Lc (c*c!msolution property independent of %

N a(N"# c!m m=0.5 c"0.5$7C7de Cennes et al7,L7$(ys7)$aris*, JG, 4->4 )4/G>*Tomislav Vuleti, Institut za fizikuSemidilute re'ime c$%&"0.5c$%&"0.'' c$%&"0.526 mode len't( scale E correlation len't( c$%&"0.''Low !%& concentrations%o added salt E !enaturationMLocally +uctuatin' re'ionsNit( eBposed (ydrop(opic coresdeCennes correlation len't(2ydrop(obic polymers0Tomislav Vuleti, Institut za fiziku$ure water 26 mode len't( scale E !ebye screenin' len't( c"0.5IsO 4 m# added salt0 c$%& ( #Is corr7len't(0 #Is > c$%& !ebye len't(0 "1 O41nm "1 &dded salt screens 5oulomb potentialTomislav Vuleti, Institut za fiziku&dded salt L6 relaBation probes t(e structureof t(e sin'le biopolymer in solutionTomislav Vuleti, Institut za fiziku&vera'e size of t(e c(ain 3 c(ain is a random walkof correlation blobs g monomers inside c"0.5 blob ) g c ' c(ain0 Ng correlation blobs c(ain size0 R (Ng!0.5 ) R c"0.#5Semidilute re'ime L6 mode len't( scale E c(ain sizeLLF O R c$%&"0.#5Tomislav Vuleti, Institut za fiziku$ure water L6 mode len't( scale E persistence len't(!%& structural persistence len't(Lp 81 nm(*!(*+l!orientational correlation of c(ain se'ments decreases as Pcos)*IKeBp)-l /Lp*81 nmTomislav Vuleti, Institut za fiziku&dded salt 5onclusionTwo relaBation modes;elaBation times are related to fundamental len't( scales for )semi*dilute solutions26 mode desribes t(e structure9or'anization of t(e ensemble of macromolecules E t(e solution QstructureR de Cennes correlation len't(L6 mode describes t(e conformation of a 'iven molecule5(ain size&ddin' salt promotes ot(er len't( scales!ebye screeenin' len't( instead of t(e correlation len't($eristence len't( instead of t(e c(ain sizeL6!S may provide more info on t(e polyelectrolyte t(en S3raysTomislav Vuleti, Institut za fiziku $oisson3"oltzmann equation!ebye32uckel approBimationrrdr r d 022) ( ) ( =T k r e zB i