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t 2. I. S. t 1. Moniulotteinen moniydin NMR-spektroskopia Proteiinien rakennetutkimusmenetelmä. NMR-spektroskopian perusteet. B ( t ). M + ( t ). t. M ( t ). t. NMR-spektroskopian teoriaa. H ( t ). B ( t ). M + ( t ) Tr{ s ( t ) F + }. M + ( t ) Tr{ s ( t ) F + }. M + ( t ).
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t2 I S t1 Moniulotteinen moniydin NMR-spektroskopiaProteiinien rakennetutkimusmenetelmä
NMR-spektroskopian perusteet B(t) M+(t) t M(t)
t NMR-spektroskopian teoriaa H(t) B(t) M+(t) Tr{s(t)F+} M+(t) Tr{s(t)F+} M+(t) s(t) M(t)
Odotusarvo Y(t) c3(t) c2(t) c1(t) Tiheysmatriisi
B(t) M+(t) t M(t) Odotusarvo Poikittainen magnetisaatio
B(t) M+(t) t M(t) Odotusarvo Poikittainen magnetisaatio
Tiheysoperaattorin liike Schrödingerin yhtälö Y(t) c3(t) c2(t) c1(t)
Tiheysoperaattorin liikeyhtälö Liouville-von Neumann yhtälö
Ratkaisu Liouville − von Neumann yhtälö
B3 s(t) b3(t) b2(t) B2 b1(t) B1 Tiheysoperaattorin liike Tiheysoperaattori kantaoperaattoreina Kantaoperaattorit
Vuorovaikutukset Liike
Vuorovaikutukset Liike
I rf-pulssi
Kytkentä t I t1 S
H N Ca CO Gz 15N-13Ca-1H korrelaatiospektri
Informaatiota kolmiulotteisesta rakenteestaLyhyet protoni-protoni etäisyydet
d D Informaatiota kolmiulotteisesta rakenteestaSidossuunnat
JHACA JHACO JHAN JHAN JCACO JCACB JHACB Sidossuunntien määrittäminenjäännösdipolikytkennöistä Esim.
2CazC’z 2CazC’z 2CayC’z 2CayC’z JCaC’ Cax JCaC’ Cax t3 t1 Ca t2 C’ N Gz w w JHACO-kytkennän mittaus Ha
JHACO JCACO JCACO ja JHACO-kytkentöjen mittaus CO Ha
“PrP Gedanken experiment” Burns CS, et al. Biochemistry. 2002 41, 3991-4001. , Biochemistry. 2002 42, 6794-6803.
How to use Residual Dipolar Couplings to study Flexible Protein Segments − A Practical Guide
How to use Residual Dipolar Couplings to study Flexible Protein Segments − A Practical Guide
t2 I S t1 Moniulotteinen moniydin NMR-spektroskopiaProteiinien rakennetutkimusmenetelmä
Odotusarvo B(t) M+(t) t M(t) Beff(t) t
Moniulotteinen moniydin NMR-spektroskopiaProteiinien rakennetutkimusmenetelmä
Moniulotteinen moniydin NMR-spektroskopiaProteiinien rakennetutkimusmenetelmä
Shortle D. and Ackerman M.S. Persistence of native-like topology in a denatured protein in 8 M urea.Science. 2001 293, 487-9. RDCs = 0 RDCs 0 RDCs 0 Sign Size Form Variation
Origin of RDCs from a flexible segment The elongated conformation will fit closer to the wall. There is more volume for the elongated conformation. Concentration of the elongated conformation is higher! RDCs are biased towards elongated conformations!
n l Q N-n Random-flight chainA model of a denatured protein z
PolyGlu Terminus PolyGlu Center Sign Size Form Variation Calculated alignments for chains Pro Glu Gly Sign Random Flight
On obstruction induced conformational changesDoes the medium perturb the ensemble?
n Q Q z Calculation of segmental alignments with and without conformational changes With Without z
Sign Sign Sign Size Size Size Form Form Form Variation Variation Variation JHACA JHACO JHAN 21-mer polyglutamate JHAN JCACO JCACB JHACB No evidence of conformational changes Expected results on the basis of calculations With Without
Sign Size Form Variation What is the source of variation in RDCs? Variation in flexibility? Glu/Pro/Gly
What is the source of variation in RDCs? Variation in amino acid orientations? Asp Glu Asp Ser Glu Glu Cys Glu Ser Cys
Sign Size Form Variation What is the source of variation in RDCs? Variation in amino acid orientations? Asp Glu Asp 2x Ser Glu Glu Cys Glu Ser Cys
Sign Sign Size Size Form Form Variation Variation What is the source of variation in RDCs? Variation due to local structures? Asp Glu Glu Ser Glu Asp Cys Glu Cys Ser low pH
Sign Size Form Variation What is the source of variation in RDCs? Variation due to motifs? Glu Glu Ser Asp Ser Cys Asp Glu Cys Glu