підручники. біохімія / Uchebnik_po_Biokhimii_E_S_Severin

CTBJieHIDI rrpou,eccoB )!(H3He.Ll,e51TeJibHOCTH HCTIOJib3YIOT Xl1Ml1'IeCKYIO 3Heprn!O. lfayqeHtt:eM npeBpa111,eHHH 3Heprntt:, conpoBO)K,lla!Olll,HX XHMH'IeCKHe peaKUHH, 3aHHMaeTCSI 6tt:03HepreTtt:Ka, HJIH 6tt:OXH- MH'-leCKa5ITepMO.Ll,IlHaMtt:Ka.

A. CB060)1JIMI 3HEPfJUI JI 3AKOHbl

TEPMO,IIJIHAMHKH

.IKtt:Bbie opraHM3Mbl c TO'IKH3peHHSI TepMO.Ll,H- HaMHKH - OTKphITbie CHCTeMbI. Me)l(Jly CHCTeMOH H 0Kpy)Kaio111,etl: cpe,L1,oti B03MO)KeH o6MeH 3Heprntt:, KOTOpbIH npo11CXO.Ll,HT B COOTBeTCTBHH c 3aKOHaMH TepMO.Ll,HHaMHK11.

I. 3aKOHbl mepMoOUHa.MUKU

TiepBbIH 3aKOH - 3aKOH coxpaHeHIHJ 3Heprtt:tt:; era MO)KHO c<t>opMyJrnpoBaTb rnK: 06111,mi 3HeprHSI CHCTeMbI 11 OKpy)KalOlll,eH cpe.Ll,hI - BeJIH'IHHanoCTOHHHaH.

BttyTpH paccMaTp1rnaeMoi1 c11cTeMbI 3Heprmr MO)KeT nepeXO.Ll,MTb OT O.Ll,HOH ee '!aCTM K .Ll.PYfOH HJIH rrpeBpa111,aTbCH .113 O.Ll.HOH <t>opMbI B .Ll.PYfYlO·

BTopoH. 3aKOH rnacnT, 'ITO Bee qm311qecKHe 11 XMMH'IeCKMe npou;eCChI B CMCTeMe CTpeMHTCH K Heo6paTMMOMy nepexo.Ll,y IIOJie3HOH 3HeprMM B xaOTH'IeCKYIO, tteynparurneMyro <PopMy. MepoH. nepexo.D.a MJIM HeynopH.Ll,O'IeHHOCTHCMCTeMhl CJIY)KMT BeJIM'IMHa, Ha3hIBaeMaH 3HTpon11eH. (S), OHa .Ll,OCTMraeT MaKCMMyMa, KOf.Ll,a Cl1CTeMa npHXO.Ll,HT B MCTMHHOe paBHOBecne c OKp~a10111,eif cpepotl:.

2. C6o6oiJnan ::Jnepzua

Ka)K.Ll.oe oprattnqecKoe coe.D.tt:Hett11e, rrocryna10111,ee B opraHM3M M3BHe MJIM BXO.Ll,Hlll,ee B COCTaB )i(l1BOM MaTepMH, 06Jia,L1,aeT orrpe.Ll,eJieHHhIM 3anaCOM BHYTpeHHeH 3Hepnm (E). lfacTb 3TOH BHYTpeHHeH 3Heprtt:M MO)l(eT 6bITb MCIIOJib30BaHa )],J1H c0Beprnett11H none3HOti: pa6oThI. TaKyIO 3Heprmo CMCTeMhI Ha3bIBalOT CB060)J:HOH 3Heprneif

ITpn rrocToJIHHhIX TeMneparype 11 )J,aBJieHMM coOTHornettne Me)K)ly H3MeHeHMeM CB060)J:HOM 3HeprnM CMCTeMbI (.~G) H 113MeHeHHeM 3HTPOIIMM (,1.S)

MO)l(HO npe.Ll,CTaBHTh CJie)J,YIQlll,MM ypaBHeHMeM:

~G = ~H - TxS, r.D.e ~H - H.3MeHeHMe 3HTaJibTIMM (BHYTPeHHeH 3Hepnrn MJIH TeTIJIOTbl, CO.Ll,ep-

)!(ameH.c51 B cttcreMe); T - a6comorHa51 reMrrepazypa. B ycJIOBH51.X, rrptt KOTOphIX nporeKaior 6ttoXHMtt'lec.KHepeaKUHH, AH rrptt6Jitt3ttTeJihHO paBHO AE (tt3Mettettmo BttyrpetttteH. 3tteprntt cttcTeMhI B pe3yJihTaTe peaKUHH). ,UJI51 6HOJIOTWieCKHX CHCTeM l13MepeHHe CB060)lHOH 3HeprHH npOH3BOMT 06b1qHO npM craH,LJ,apTHhIX YCJIOBIDIX, KOr)la pH 7,0, TeMneparypa 25 °C, BCe paCTBOphl HaXOMTC51 B KOHuempaUHH l MOJih/JI, a BCe Ta3hI nptt ,llaBJieHHM B ] aTM.

Ilptt CTaH,LJ,apTHhIX YCJIOBMX BCe cPYHKUMH o6o3HaqaJOT KaK AG0', AS0' tt AH0'. 113Mettetttte craH- ,!!,apTHOH CB060.UHOH 3Heprntt (AG0') MO)!(HO BhlqHCJIHTh, 3HaH KOHCTaHTY paBHOBeCH51 (K'eq) XHMHqecKOH peaKUI1H.

3. 3HiJepzonu11ecKue u :J1CJepzonu11ec1Cue peaKu,uu

HanpaBJieHtte XHMJ1qeCKOH peaKLJ,HH onpe)leJ151eTC51 3HaqetttteM AG. Ecntt 3ra BeJittqHHa orpttuaTeJihHa, TO peaKUH51 npoTeKaeT caMonpoH3BOJihHO l1 conpOBO)i()laeTC51 yMeHhllieHHeM CB060)lHOH 3Heprnw. TaKHe peaKLJ,MM Ha3hIBaJOT 3K3eprottttqecKHMM. Ecntt nptt 3TOM a6comoTHOe 3Haqetttte AG BeJittKo, TO peaKUH51 M.lleT rrpaKTttqecKM .llO KOHUa, 11 ee MO)!(HO paCCMarp11BaTh KaK Heo6paTMMYIO.

Ecntt AG rroJIO)!(MTeJihHO, ro peaKUIDI 6y)leT rrpoTeKaTh TOJlbKO rrptt IIOC'fYIIJiemrnCB060.UHOH 3Hepfl1H l13BHe; TaKHe peaKUHH Ha3hIBaJOT 3H,LJ,eprOHHqecKMMH.

Ecm1 a6conJOTHoe 3Haqemie AG BeJIHKO, TO CHCTeMa ycroH.qMBa, H peaKUIDI B TaKOM CJIY'lae npaKTHqecKH He ocyr.u,ecTBJ15IeTc51. IlpH AG, paBHOM HYJIJO, CHCTeMa HaXOLlHTC51 B paBHOBeCMH (ra6n. 6-1).

4. Conpn:HCenue 31CJepwnu11ecKux

u 3niJepzonu11ecKux npou,ecco6 6 opzanU3Me

B 6Honortt'-lecKMXcttcTeMax repMO.UttHaMwqec- KH HeBhITOLlHhie (3H,lleproHJ1qeCKHe) peaKUHH MO- ryr rrpoTeKaTh JIHWh 3a cqer 3HeprttH 3K3eproHtt-

Ta6mn.ia 6·1. COOTHOWeHMe Me>t<Ay eenM"IMHaMM K'eq.., AG0'..,

qecKHx peaKUttH. TaKtte peaKUHH Ha3hIBaIOT 3HepreTtt'leCKHconp51)!(eHHhIMH. MHortte M3 3THX peaKUMH npottCXOMT nptt yqaCTHM a)leH03HHTPHcPOC- <Para (AT<I>), ttrpaIOrn:ero poJih conpHraIOmero ¢laKTOpa.

PaccMoTpHM no,!!,po6Hee 3HepreTm:-••y conpmKeHHhrx peaKLJ,Mtt Ha npttMepe ¢ioc¢iopMJIHpoBaHM51 rJilOK03hI.

PeaKUIDI ¢ioc¢iopttnttpoBaHtt51 rnJOK03hr cBo6o)l- HhIM ¢ioc¢iaroM c o6pa3oBatttteM rnIOK03o-6-¢ioc- <Para 51BJI51eTC51 3H)leprOHttqecKOtt:

(l) fJIIOK03a+ H 3P04 4 fJIJOK03o-6-¢ioc¢iaT +

H 20 (AG= +13,8 K):QK/MOJib).

.ll,.rr51 npoTeKattHH raKott peaKLJ,HH B cropoHy o6pa3oBaHMH rJIIOK030-6-¢Joc¢Jara He06XO)lHMO ee COnpmKeHtte c ,llpyroi1: peaKu,ttei1:, BeJ1ttqHtta cBo6oaHOH 3HeprnH KOTopo:H 6oJihrne, qeM Tpe6yeTC51 )JJl51 ¢ioc¢iopMJIMpOBaHH51 rJIIOK03bI.

(2) AT<I> 4 A,IJ,<l> + H 3P04

(AG = -30,5 K):QK/MOJ1h).

Ilptt conpIDKeHHtt rrpoueccoB (I) H (2) B peaKUHH, KaTaJIH3HpyeMOH reKCOKHHa30H (CM. pa3,!1,eJI 7), ¢ioc¢iopHJIHpoBaHHe rmoK03hI nerKo nporeKaer B <Ptt3wonorttqecKwx ycnoBttHx; paBHOBectte peaKUMH Cl1JlhHO C.UBHttyTO BnpaBo, l1 OHa rrpaKTtt'leCKHHeo6parnMa:

(3) fJIJOK03a + AT<I> 4 fJIJOK03o-6-¢ioc¢iaT +

A,IJ,<l> (AG = -16, 7 K,lJ;)!(/MOJib).

.6. XAf>AKTEPHCTMKA Bh1COK03HEPI'EIWIECKIIX

<I>OC<I>ATOB. Qu:K.JI AT<l>-A,U<I>

B )l(HBhIX opraHtt3Max cyw:ecTByeT uena51 rpyrrna opraHWleCKMX ¢ioc¢laTOB, rlI)lpOJIH3 KOTOpbIX npMBOLlHT K OCB060)!()leHMIO 60JihllIOTO KOJittqeCTBa cBo6onttoH: 3Hepnrn. TaKHe coem1ttett1rn tta3hIBaJOT BhICOK03HepreTttqecKHMH ¢ioc¢iaTaMH (ra6n. 6-2).

HanpaeneHMeM XMMM"leCKMX peaKl.IMM

KaK Btt)lHO tt3 rn6JI. 6-2, pa3Hhie <Poc<PopttJittpoBaHHhie coemrnemrn 06Jia,i::ia10T pa3HhIM JarracoM cB060,llttoti 3Hepnur. K rpyrrrre BhICOK03HepreTw1ecK11x <Poc<PaTOB, noMHMO AT<I>, OTHOCHT ettoJI<t>oc<PaTbI, attrH,llpH,llhI 11 <Poc<PoryaHH,lIHHhI. Coe)lHHeHH5I, pacnoJIO)!(eHHbie B HH)!(tteti: qacTtt Ta6JIHU,bl, COCTaBJ15IJOT rpynny HH3K03HepreT11qecKHX <Poc<PaToB. UettTpaJihttoe MecTO cpe)lH 3THX coe,lIHHeHHti JaHHMaeT AT<I> (p11c. 6-2).

AT<I> - MOJieicyJia, 6oraTM 3Heprnetl:, nocKOJihKY OHa CO,llep)!(HT )lBe <Poc<t>oaHrH,llpH,llHbTe CB5I3H (~, y).

ITpH rH,llpOJIH3e KOHU,eBOH <t>oc<t>oattfH)lpH,llHOH CB5I3H AT<I> rrpeBpamaercH B A,II,<I> H opro<Poc<PaT P;. ITptt 3TOM H3Mettetttte cBo6o)lHOH 3Heprntt cocrnBAAeT KKaJI/MOJib. ITptt ycJIOBH5IX, cymecrnyJOIUHX B KJTeTKe B HOpMe (pH 7,0, TeMrreparypa 37 °C), <PaKTttqecKoe 3Haqetttte ~G0' ,lIJIH rrpouecca I11,llpoJIH3a cocTaBJI5IeT OKOJIO -12 KKaJI/MOJih. Ben11q11tta cBo6o)lHOH 3HeprnH rH,llpOJitt3a ,lleJiaeT B03MO)!(HbIM ero 06pa30Batt11e H3 A,II,<I> Ja cqeT rrepettoca <Poc<t>arnom OCTaTKa OT TaKHX BhTCOK03HepreTttqecKHX <Poc<t>aToB, KaK, ttanp11Mep, <Poc<PoettoJI-

rmpyBaT MJUI 1,3-611cc):locc):lorm1uepaT; B CBOIO oqepe)l.b, AT<t> MO)l(eT yqacTBOBaTh B TaKJ.fX 3H)J.eprott11- Y:ecK11X peaKUIDIX, KaK c):locc):lop1VrnposaH11e rmoKo3hI l1Jll1 rn1111,ep11Ha. AT<t> BhiczyrraeT B pon11 JJ.OHopa 3Heprn11 B 3H)J.eproH11Y:eCK11X peaKUIDIX MHOIBX aHa6oJTl14eCKl1X rrpoueccoB. HeKoTOph1e 611ocMHTeTmecKtte peaKU1111 B opraHH3Me MOryr rrpOTeKaTb rrp11 yy:aCTHl1 JJ.pyrnx ttyKJie03HJJ.TpHCpocc):laTOB, aHaJIOfOB AT<l>; K Hl1M OTHOCITT ryaH0311HTPH<POCcpaT (IT<l>), YPHJJ.l1HTp11cpocc):laT (YT<t>) 11 UHTl1JJ.l1HTp11c):locc):laT (UT<l>). Bee 3Tl1 ttyKJTeOTHJJ.hI, B CBOIO oqepe)l,b, o6Pa3YJOTC51 rrp11 11crroJTh30BaHH11 cBo6oJJ.HOH 3Hepm11 KOHUeBoif cpoccparnoif rpyrrrrhI AT<D. HaKotteu, 3a cqeT coo6oJJ.Hoif 3HeprHH AT<t> coBeprnaroTcH paJn11qHh1e BHJJ.hl pa60ThI, JTe)l(alll,tte B OCHOBe )1(113He- )l.e51TeJTbHOCTl1 opraHH3Ma, Hanp11Mep, TaKl1e KaK MblllieqHoe COKpaw,eH11e HJTl1 aKTHBHhIH TpaHCIIOpT Be111,ecrn.

TaKHM o6pa30M, AT<t> - rnaBHhIH, HenocpeJJ.- crneHHO HCIIOJTh3yeMbIH JJ.OHOP CB060JJ.HOH 3Hepfl111 B 611onomy:ecK11x c11cTeMax. B KJTeTKe MOJTeeyna AT<l> pacxoJJ.yeTCH B TeY:eH11e OJJ.HOH MHHyThI IIOCJTe ee o6pa30BaHH51. Y Y:eJTOBeKa KOJTHY:eCTBO AT<t>, paBHoe Macce Tena, o6paJyeTcH 11 pa3pyrnaeTCH Ka)l(Jl.ble 24 4.

l1crroJTh30Batt11e AT<t> KaK ttcToqH11Ka 3Hepr1111 B03M0)1(H0 TOJThKO np11 ycnOBHH HerrpepbIBHOfO CHHTe3a AT<l> 113 A,ll,<D 3a cqeT 3Hepm11 oKMcneHHH oprattl14eCKl1X COeJ].HHeHl1H (p11c. 6-3). ll,11KJT

ATct>

AT<l>-Nl<l> - octtOBHOH MexaHHJM o6Metta 3Hepm11 B 611onornqecKHx c11cTeMax, a AT<l> - yttHBepCaJThHaH «3HepreT11qecKa5I BaJTIOTa».

B. 0KHCJU1.TF.JlhHO-BOCCTAHOBMTF.JihHhIE

PEAKQMM. OKMCJIMTF.JihHO-

BOCCTAHOBllTF.JihHhlM IlOTEHQIIAJI

ITOJJ. OKHCJTeH11eM IIOHHMaIOT OTW,errJTeHHe 3JieKTpOHOB, a ITO)]. BOCCTaHOBJJeHl1eM - rrp11coe)l.HHem1e 3JTeKTpOHOB. 0Kl1CJTeHHe Jl.OHOpa 3JJeKTpOHOB Bcer)l.a COIIpOBO)((,IlaeTCH BOCCTaHOBJTeH11eM aKUeIImpa 3JTeKTpOHOB. 3TOT Ilp11HUHII OKHCJTl1TenhHOBOCCTaHOBHTeJThHbIX npoueccoB np11MeHHM H K 6110XHM11Y:eCKHM c11cTeMaM. B nro6oif OKHCJT11TeJTh- Ho-noccrnttoB11TeJThHOH peaKUHH yqacrnyeT aKuerrTOP 3JTeKTpottoB (0K11cn11Tenh) 11 JJ.Ottop 3neKTpoHOB (BoccrnttoB11Tenh). Harrp11Mep:

(1) Cu+ 0 ~ Cu2+02-.

CYMMaPHYJO peaKUHIO ( 1) MO)l(HO ycnoBtto pa3JJ.en11Th Ha 2 nonypeaKu1111 (2), (3):

(2)Cu - 2e ~ cu2+.

(3)0 + 2e ~ 0 2-.

B Ka)l(Jl.OH 113 HHX yY:acrnyeT oKMcneHHaH 11 BOCcrnHoBJJeHHaH cpopMa OJJ.HOfO coeJ].11HeH115I; HX Ha3bIBaIOT conpIDKeHttoit rrapoif, HJTH peJJ.oKc-napoif.

Ta6mn1a 6-3. CTaHRSPTHb1e OKMCn1tTenbHo-soccTaHoB1tTenb-

Hb1e noTeHl.IM8nbl HeKOTOpblX conp11lKeHHblX nap

Pa3Hhie pe11,0Kc-naph1 o6JiaJJ,aIOT pa3JUILJHhIM cpo.ucrnoM K 311eKTpoHy. Te, y KOTOPhIX 3TO cpo11,- crno MeHbIIIe, OTJJ,alOT 3JleKTpOH TeM, y Koro OHO 6011bIIIe. Mepo:H cpo)J,crna pe11,0Kc-napb1 K 3JleKTpoHy CJI~HT OKHCJl11TeJlhHO-BOCCTaHOBHTeJlhHhlH TIOTeHUHaJI, HJIH pe)J,OKC-IIOTeHUHaJI (Eo'), Be1111LJl1Ha KOTOporo Henocpe)J,CTBeHHO CBH3aHa c H3MeHeHHeM CB060)J,HOH 3Hepnm. BeJil1'-II-IHY E0 '

Bbipa)[(aJOT B BOJihrax; LJeM OHa MeHbllle (0Tp11ua-

TeJihHee), TeM MeHhwe cpoiJ,CTBO Bemecrna K 3JieKTpOHaM. '-leM60JibIIIe cpO)J,CTBO, TeM 60Jlbllle BOC-

craHOBHTeJihHhlH TIOTeHUHaJI.

PeiJ,OKC-noreHU11aJihT E0' CBH3aHhI c H3MeHeHHeM cB060!1,Ho:H 3Hepnrn ypaBHem1eM Hepttcra:

3JleKTpOH-)],OHOPHOH H 3JleKT))OH-aKUerrropHOH nap. Be1111LJHHa ~E0' - CTaH)J,apTHaH BeJlHLJHHa OKHC- JlHTeJlhHO-BOCCTaHOBHTeJlhHOro TIOTeHUMaJia; ee onpeJ],eJlHIOT B CTaH!1,apTHhIX yCJlOBHHX, KOrJJ,a KOHueHTpaum1 Bcex Bemecrn paBHhI 1 M, !1,aBJlett11e

ra30B COCTaBJI5IeT 1 arM, a pH 7,0 (ra6JI. 6-3).

r. OcHOBHhIE 3TAilhl TPAHC<l>OPMAU,HH 3HEPfHH KATABOnMqECKHX TIPOUECCOB

3tteprnH ocso6o)[(JJ:aeTCH B rrpouecce Q:>epMettraTHBHOro OKHCJieH1151 Mera60JIHTOB crreump11qeCKH-

MH J],erH)J,poreHa3aMM. B peaKUHHX J],erH,D,pHposaH11H 3JieKTpOHhl 11 npoTOHhl nepeXOMT OT opraHHLJeCKHX cy6cTpaTOB Ha KocpepMeHThI NAD- H FAD-3aBHCH- MhIX !1,erH,D,poretta3. 3JieKTpOHhI, o6Jia!1,aIOIUHe BhIcoKHM 3HepreTHLJecKMM rroreHU11aJIOM, nepe)J,aIOTcsi or ooccTattoBJleHHhIX KocpepMeHToB NADH H FADH2

K KHCJIOpOiJ,Y qepe3 uerrh rrepeHOCLJHKOB, JIOKaJIH30BaHHbIX BO BHyTpeHHeil MeM6paHe MlITOXOH!1,pHH. BoccrattoBJlett11e MOJieeyJihr 0 2 npo11cxo!1,HT B pe3YJihTaTe rrepettoca 4 3JieJCTpOHOB. IlpH Ka)[(JJ:OM rrp11coe)J,11HeHHH K KHcJiopo!1,y 2 3JieKTpOHOB, nocrynaIOTUHX K HeMY ITO ueITM rrepeHOC'-111KOB,113 Marp11Kca rrornoma10rcsi 2 nporotta, B pe3yJihrare qero 06pa3yercH MoJieeyJia Hp.

0KHCJieHHe opraHHLJeCKHX BemecrB B KJieTKax, corrpoBO)[(JJ:aIOmeecH rroTpe6JiemieM KHCJiopoiJ,a 11 CHHTe30M BO)J,hl, Ha3hIBaIOT TKaHeBhIM )],bIXaHHeM, a uenh rrepettoca 3JieKrpottoB (UII3) - !1,hrxare11htto:H uenhIO.

3JieKrpotthI, rrocryrraIOTUHe B UII3, no Mepe 11x npo!1,BH)[(eH1151 OT 0)1,HOro nepeHOCLJHKa K ,n;pyroMy repHIOT CB060!1,HYIO 3HeprHIO. 3HaLJl1TeJihHaH qacrh 3TOH 3Hepnm 3arracaerrn B cpopMe AT<l>, a qacTh 3Hepr1111 pacce11BaeTcsi B BH,n;e TeIIJia. KpoMe roro, 3JieKTp0Hhl c BhICOKHM 3Heprerlfl-leCKHM noTeHUHaJIOM, B03HHKalOTUHe npH OKHCJieHl111 pa3JIH'-IHhIX cy6crpaTOB, MOryT 6bITh HCTIOJih30BaHbl B peaKUH - HX 6Hoc11ttre3a, JJ,JIH KOTOph1x noMHMO AT<l> Tpe6yIOTCH BOCCTaHOBHTeJibHbie 3KBHBaJieHThl, HanpHMep NADPH.

~. <l>EPMEHThl H KO<l>EPMEHThI,

Y'IACTBYIOIIIME B OKMCRMTEJihHO-

BOCCTAHOBHTEJihHhIX PEAKUMHX

IlepeHOC 3JieKTpOHOB OT OKHCJIHeMhlX cy6cTpaTOB K KHCJIOpo,n;y npOHCXO)],HT B HeCKOJlhKO 3Ta-

ITOB. B tteM yqacrnyer 6oJihIIIOe KOJIHLJ:ecrno rrpoMe~oqtthrx nepeHOCLJHKOB, Ka)[(JJ:hlH 113 KOTOphlX crroco6ett npHcoe,n;HHHTh 3JieKTpOHhI OT rrpeiJ,hWYmero KOMIIOHeHra 11 rrepe!1,aBaTh cJie,n;yIOIUeMy. TaK B03HHKaer uenh OKHCJIHTeJibHO-BOCCTaHOBHTeJib- HbIX peaKUHH, B pe3yJihTaTe l.Jero rrpOHCXO)],HT BOCCTaHOBJleH11e 0 2 11 c11me3 H 20. B !1,hIXaTeJlhHYIO uenh MHTOXOH!1,pHil BXO)J,HT 60JihlllOe LJHCJIO rrepeHOCl.JHXOB (pHC.

3a HCKJIIOLJeHHeM y6HXHHOHa (KoQ), Bee KOMIIOHeHThl Uil3 - 6eJIKH. B cocraBe 3THX 6eJIKOB COJJ,ep)I<:aTCH pa3JIHLJ:Hhle He6eJIKOBhie KOMIIOHeHThJ: FMN, Fe B cocraBe )KeJie3o-ceptthIX 6eJIKOB 11 B cocraBe rropcpttpHHOBhIX KOJieu, 110HhI Cu.

I. IlepBU'IHble a«u,enmopbt BoiJopoiJa

TiepBll'IH.bieaK.I.J,eilTOpbl BO,n:opo,n:a OKMCJUITeJihHOBOCCTaHOBMTeJihHhIX pe(lI(QMi1 OTHOCHT K 2 TI!ITaM nefll,ll;poreml.3: ID:IKOTIIBaMl1,ll,JaBifCHMhIM, co,n:epxau.I.I,HM B KalJ.ecrne KOcPepMeHTOB rrpoH3BO)J,Hhie HHKOTHHOBOtt KMCJIOThI, H qmaBHH3aBHCHMbIM, co,n:ep)l(Clll.l,HM npOH3BO)J,Hhie ptt6ocpnaBHHa (CM. p33,lleJI 2).

HttKOTHHaMH,n:3aBHCHMbie ,n:erH,n:poreHaJhl co,n:ep- )l(ClT B Kaqecrne KOcpepMeHTOB NAO+ wrn NADP+ (cM. paJ,n:en 2). NAO+ H NADP+ - npott3BO,n:Hhle BHTaMttHa PP. 3Ttt KocpepMeHThI Bxo,n:m B cocrnB aKTHBHhIX ueHTPOB nerH,n:poreHa3, Ho Moryr o6paTHMO Jl:HCCOI.1,HHPOBaTb H3 KOMIUieKca c ano¢epMeHTaMH H BKJIIOqaroTCH B COCTaB cpepMeHTa B xone peaKI.J,HH. Cy6cTpaThI NAO- H NADP-3aBHCHMhIX ,n:ern,n:poreHa3 HaxO,n:HTCH B MaTpHKCe MHTOXOtt,n:pHtt H B I.J,HT03one. Pa6oqei1 qacThlO HHKOTHHaMH,n:HhTX KOcpepMeHTOB CJIY)IGIT HHKOTHHaMH,n: (pHC.

EOJiblllHHCTBO ,n:errr,n:poreHa3, rrocTaBJIHIOlilHX 3JieKTpOHhI B U:TI3, co,n:ep)KaT NAO+. Otttt KarnJIH3ttpyroT peaKUHM THTia:

R-CHOH-R1 +NAO+ H R-CO-R1 + NADH + H+.

TaKHM o6paJOM, NAO+, nprrcoe1:r:imHH npOTOHhI M 3JieKTpOHhI OT paJJimHhIX cy6crparoB, cn~ rnaBHhIM KOJIJieKTopOM 3Hepfltl1 OKMCJUleMbIX BelileCTB H rnaBHbIM HCTOlJ.HMKOM 3JieKTpOHOB, 0611a,n:a10lilMX BblCOKMM 3HepreIWieCKHM TIOTeHI.l,HaJIOM, IIJIH U:TI3.

NADPH He HBJrneTcH Herrocpe,n:cTBeHHhTM ,n:ottopoM 3JieKTpOHOB B UTI3, a 11cnonb3yeTcH noIJ.T1111cKJIIOIJ.MTeJihHO B BOCCTaHOBMTeJibHbIX 6ttOCHHTe3ax (cM. paJ.ue11 8). 0.IJ.HaKo B03MO)l(HO BKJiroqemre 3JieKTpOHOB c NADPH B UTI3 611aro,n:apH .uewcrnttro nttptt.IJ.11HttyKJieOTH,n: Tpattcm.uporetta3hI, Karnm1311PY10lileH peaKI.J,HIO:

NADPH + NAD+HNADP+ + NADH.

<l>naB11HOBhie ,JJ,ern,JJ,poretta3hI co.uep.11<aT B Ka'leCTBe Kocj:>epMeHTOB FAD HJI11 FMN. 3rn Kocj:>epMeHThI o6pa3yIOTCSI B opraH113Me '-!eJIOBeKa113 B11TaMl1Ha B 2 (CM. pm,!leJI 2). <l>naB11HOBb1e Ko¢epMeHThI npo'-!HOCBSI3aHhI c ano¢epMeHTaM11. Pa6oqei1: qacThIO FAD 11 FMN CJIY)KHT 1130aJIJIOKCa311HOBaSI conpmKeHHaSI U11KJil1'1eCKaSICHCTeMa (p11c.

FAD CJIY)!(11T aKuenTopoM 3JieKTpOHOB OT MHOr11x cy6CTpaTOB B peaKUHSIX THna:

R-CH2-CH2-RI + E (FAD) H R-CH=CH-RI +

E (FADH2),

r.ue E - 6eJIKOBaSI qacTh ¢epMeHrn. noJihUil1HCTBO FAD-3aB11c11MhIX ,JJ,er11,!lporeHa3 -

pacTBOp11Mhie 6eJII<l1, JIOKaJil130BaHHhie B Marp11Kce Ml1TOXOH,!lp11M. l1CKJIIO'-!ett11eCOCTaBJISieT CYKU11HaT- ,!lern,!lporeHa3a, HaXOMlllaSICSI BO BHyrpeHHeM MeM6paHe M11ToxoH,!lp11H:. K FMN-co,JJ,ep)!(am11M ¢epMeHTaM np11HaDJle)!(ttT NADH-,JJ,ern,!lporeHma, KOTOPM TaKll<e JIOKaJI.1130BaHa BO BHyrpeHtteH: MeM6paHe M11ToxoH,!lp.11i1; otta oKHCJISieT NADH, o6paJYIQIU11i1cSI B MHTOXOH,!lpttaJihHOM MarpttKCe.

2. I.(enb nepenoca :J.!le«mpono6 om NADH u FADH2na 1<uc.11opoo

nepeHOC 3JieKTPOHOB OT NAD H K 02 BKJIIO'-!aeT pSI,!l nepeHOCl.f.HKOB, KOTOphie JIOKaJI.1130BaHhI BO BHYTpeHHert MeM6paHe Ml1TOXOH,!lpttM. 3a HCKJIIO- '-!eH11eMy611x.11H0Ha .11 u11Toxp0Ma C, 3TO CJIO)!(HhJe 6eJIKOBhie KOMnJieKChl.

NADH-,JJ,em.uporeHa3a (NADH-Q-pe.uyKrn3a, KOMilJieKC I) COCTOHT 113 HeCKOJihKHX IlOJittnenTH,!l- HhIX uenei1. PoJih npocTeTtt'-!ecKortrpynnhI 11rpaeT FMN. EIJ,ttttcTBeHHhIH cy6cTpaT cj:>epMettrn - NADH, c KoToporo 2 3JieKrpoHa .11 npoTOH nepeHOC5ITCSI Ha FMN c o6pa30BaH11eM FMNH2• BTOport rrpoTOH nornowaeTcSI .113 MaTpttKca. PeaKU.1151 npoTeKaeT no ypaBHeH1110:

NADH + H+ + E (FMN) ~ NAD+ + E (FMNH 2).

C FMNH 2 3JieKTpOHht nepeHOCSITCSI 3aTeM Ha pHA )KeJie3o-ceptthIX 6eJIKOB (FeS), 11rpa10w.11x pOJih BTOpow npocTeTtt'leCKOH rpynnhI B MOJieKyJie NADH-Aer.11.uporeHa3hI. ATOMht )!(eJie3a B 3T11X 6eJIKax (HereMoBoe )!(eJie3o) co6paHhI B HeCKOJihKO rpynrr, TaK Ha3hrnaeMhIX )KeJie3o-cepHhIX ueHTpos. FeS-ueHrpbI BXOil,HT B COCTaB MHOrHX 6eJIKOB (¢JiaBorrpoTettHOB, U11TOXpOMOB), y'laCTBYIOIUHXB OK11CJI.HTeJibHO-BOCCTaHOB11TeJihHhIX peaKUJ151X. 1-fa-

BeCTHhl 3 mrra FeS-ueHTpOB (FeS, Fe2S2, Fe4S4), B KOTOpbIX aTOM )!(eJie3a CB513aH c aTOMOM cepbl ocTaTKOB Ul1CTe11tta .HJI.11 HeopraHtt'leCKOH cepht. CTpoett11e )!(eJie3o-cepHhIX ueHTpoB rroKa3aHo Ha p11c. 6-7.

N AD H -,1J,er11,1J,poreHa3a coI1,ep)!(11T tteCKOJihKO uettTpos Tttna Fe2S2 11 Fe4S4_ATOMhI )!(eJie3a B TaK11x uettTpax MOryT np11H11MaTh .11 OT)J,aBaTh 3JieKTPOHhI nooqepeIJ,tto, rrepexo,!lSI B ¢eppo- (Fe2+) 11 ¢epp11- (Fe3+) cocTOSIH1151. OT )!(eJie3o-cepHhIX ueHTpos 3JieKTPOHhI nepeHOCSITCSI Ha KOQJepMeHT Q (y6.11x11HOH) (p11c.

0603tta'-leHtte3Toro )!(11popacrnop.11Moro x11H0Ha np0.11CXO,!l11T OT rrepBOM 6YKBbI aHfJI11MCKOfO Ha3Bamm mttotta (quinone), a HaJBaHtte y6l1XllttOH orpa- )!(aeT ero rn11poKYIQ pacnpocrpatteHHOCTh B np11po.ue (ubiquitous - Be3,UeCYIUHM). MoneKYJlhI y6HXHHOHa B 33Bl1C.11MOCT11 OT 11CTO'-!H11Ka,H3 KOTOporo OHl1 Bhl- ,UeJieHhI, pa3JI11'-!aIOTCSI ,!lJ111HOH yrneBO)J,OpOil,HOM uen11, KOTopa51 y MJ1eKon.11rn10w11x coIJ,ep)!(ttT IO

113onpeH011,!lHhIX 3BeHheB 11 o603tta'-!aeTCSIKaK Oio· B npouecce rrepettoca 3JieKrpottoB c NADH-IJ,er11,!lpo- reHa3ht qepe3 FeS Ha y6l1XllHOH OH 06paT11Mo npeBpamaeTcSI B rn,LI,pOXHHOH. Y611XHHOH BhinOJIHSieT KOJIJieKTOPHYJO QJYHKUMIO, np11coe,!ll1HSl5! 3JieKTpOHhl OT NADH-IJ,ern.uporeHaJht 11 npyrnx QJJiaBMH3aB11CHMhIX ,!ler11,!lporeHa3, B '-!aCTHOCT11,OT cyKQMHaT- ,!ler11,!lporeH33bl. Y6HXHHOH yqacrnyeT B peaKUMSIX Tttna:

E (FMNH2) + Q ~ E (FMN) + QH 2.

11,HTOXpOMbl HJIH reMonpoTeHHbl npwcyrCTByIOT BO Bcex Tttnax opramf3MOB. B KJieTKax :::iyKap.110TOB OHM JTOKaJIH30BaHbl B MHTOXOH,Il,pHaJibHbIX MeM6paHax H B 3P. lfaBeCTHO OKOJTO 30 pa3JJHqHbIX JIHToxpoMOB. Bee IIHTOXPOMhI B Kaqecrne npocTeTtttiecKoif rpynnhI co.IJ,ep)((aT reM (cM. pa3.IJ,eJT 1).

Mx MHoroo6pa3.11e o6ycJToBJTeHo:

•pa3JI.11q.11eM 6oKOBhix Jieneif B CTPYKTYpe reMa;

•paJJTmtteM B CTpYKTYPe nOJmnemH)lHhIX Jienetr;

•pa3JI.11q.11eM B cnoco6e CBH3H IIOJTHnenTH)J,HblX

Jienetr c reMOM.

B 3aBHCHMOCTH OT cnoco6ttocTH nornomaTh cBeT B onpe,lleJTeHHOH qacTH crreKTpa Bee IIHTOXpOMbl

.IJ,eJTHT Ha rpynnh1 a, b, c. Bttyrptt K~otr rpyrrrrh1 OT,lleJTbHbie BH)lbl c yttHKaJibHbIMH cneKTPaJibHhlMH CBOHCTBaMH o603HaqaJOT IIHcPPOBhIMH HH,IJ,eKcaMH (b, bl'b2 H T..IJ,.).

CTPYKTYPHhie oco6eHHOCTH pa3Hhix BH.llOB IIHToxpoMoB onpe.IJ,eJTHIOT pa3JIHqHe B HX OKHCJTH- TeJThHO-BOCCTaHOBHTeJTbHhIX rroTeHJIHaJTax. B ll,IT3 yqacTByIOT 5 THilOB IIHTOXPOMOB (a, a3, b, c, cJ 3a HCKJIJO'leHHeM IIHTOXpOMa c, Bee IIHTOXPOMhl HaX0,11,HTCH BO BHyTpeHHetl MeM6paHe MHTOXOH,Il,pHH B BH,lle CJTO)l(HblX 6eJTKOBhlX KOMilJTeKCOB (Ta6JT. 6-4).

QH2-.IJ,erH,llporeHaJa (K03H3HM Q-mnoxpoM c-pe-

.IJ,YKTaJa, KOMilJTeKC Ill) COCTOHT H3 2 THilOB IIHTOXpOMOB (bl H b2) H JIHTOXpOMa cl. QH2-)lefH,llpore- Ha3a nepeHOCHT 3JTeKTPOHhl OT y6HXHHOJTa Ha IIHToxpoM c. Bttyrp.11 KOMilJTeKca III :::iJTeKTpOHbI

B11Hl'1JlbHaS1rpynna

,....---.A---..

nepe.IJ,aIOTCH OT UHTOXpOMOB b Ha FeS-ueHTphl, Ha IIHTOXPOM cl'a 3aTeM Ha UHTOXPOM c. fpynnhl reMa, rro.IJ,o6Ho FeS-JieHTpaM, rrepeHOCHT TOJThKO no O.llHOMy :::iJTeKTpotty. TaKHM o6pa30M, OT MOJTeKYJThl QH2 2 3JTeKTPOHa nepeHOCHTCH Ha 2 MOJTeKyJThI IIHToxpoMa b. B Ka'lecrne n'poMe)((YfO'lHOrorrpo-

.llYKTa B 3THX peaKJIHHX nepeHoca 3JTeKTpOHOB B03MO)((H0 o6pa30BaHtte CB060,IJ,HOro pa,11,HKaJia ceMHXHHOHa. B UHToxpoMax THna b reM He CBH3aH KOBaJieHTHO c 6eJTKOM, a B UHTOXPOMax cl H c OH npHCOe,llttHHeTCH K 6eJIKY nptt IlOMOIJIH TH03cPHP-

HhIX CBH3eH (pttc. 3Ttt CB513H o6pa3yIOTC51 rryTeM rrpHCOe,llHHeHHH 2 UHCTeHHOBhIX OCTaTKOB K BHHHJThHhIM rpyrrrraM reMa.

UHToxpoM c - nep.11<t>ep.11qecKHi1: BO.IJ,opacrnopttMhTH MeM6paHHhIH 6eJTOK c MOJTeKYJTHPHOH Macco:H

12 500 ,[I,, HMeIOIUHH 0.llHY IlOJIHilenTH)lttym uenh .113

100 aMHHOKHCJTOTHhIX OCTaTKOB, H MOJieKYJIY reMa, KOBaJTeHTHO CBH3aHHYIO c IlOJTHnenTH,llOM.

l.I,HTOXPOMOKCH,IJ,a3a (KOMilJTeKC IV) COCTOHT H3

2 IIHTOXPOMOB THTTa aa3 K~hTH .113 KOTOpbTX HMeeT ueHTP CBH3hTBaHHH cKHCJTOPO.llOM. l.I,ttTOXpOMbl a tt a 3 ttMeIOT xapaKTeptty10 )((eJTe3onop<t>ttpttHO-

ByIO npocTeTH'leCKYIOrpynrry, Ha3hIBaeMym reMOM A H OTJTHqaJO~CH OT reMa IIHTOXPOMOB c " cl (pttc. 6-10). Ott co.IJ,ep)((HT <t>opMHJihHyIO rpyrrny BMeCTO 0,11,HOM H3 MeTHJihHhIX rpynn " yrneBO,llOPO.llHYIO Jieilh BMeCTO O,llHOH H3 BHHHJThHhIX rpynn.

).l,pyraH oco6eHHOCTh KOMilJTeKca a-a3 - HaJTHqtte B HeM HOHOB Me)lH, CBH3aHHhlX c 6eJTKOBOM