Bioinorganic Chemistry

生物無機化学
Bioinorganic ChemistryPart 2

Bioinorganic Chemistry

ᴥ章Ჽ酸素輸送᷑ḅᷣ᷁質ᴥ᳐ᴣ᷂᷿ᷪᷴᷥḅᴥ᳐ᴤᷪᷲᶺᷚ᷼᷼ḅᴥ᳐ᴥᷪᷴ᷉ᶴᷝḅ

酸素輸送᷑ḅᷣ᷁質

Bioinorganic Chemistry!"#$%&'()
Dioxygen Carrier Proteins!"#$%&!'()*)&!"+,-&

proteins

Hemoglobin (Hb)

Hemerythrin (Hr)

Hemocyanin (Hc)metaloxidation state
deoxy/oxymetal:O2
sourceFe-porphyrin(II)/(III)dinuclear Fe(II)/(III)dinuclear Cu(I)/(II)

2Fe : O2
marine invertebrates

2Cu : O2
arthropods
mollusks
blue
colorlessprotein side chains400-20000 kDamany

Fe : O2
all vertebrate
many invertebrates
color, oxy-form redcolor, deoxy-form red-purple
coordination
porphyrin
Mw
65 kDanumber of4subunits!"#$%&

Myoglobin (Mb)violet-pinkcolorlessprotein side chains
108 kDa
8

酸素輸送᷑ḅᷣ᷁質

Bioinorganic Chemistry!"#$%&'()*+,-E
FC

COO-NNN
マッコウクジラのミオグロビン(Mb)のＸ線結晶構造
153アミノ酸残基，A-H8個のヘリックス構造（ヴォート）FeCOON

NHeme

酸素輸送᷑ḅᷣ᷁質

Bioinorganic Chemistry!"#$%&'()*+,β1

α2Fヘリックス

α1

β2
デオキシヘモグロビンの結晶構造
α2β2サブユニット四量体

deoxyHb α鎖のヘム周辺の構造（T状態）Bioinorganic Chemistry

酸素輸送᷑ḅᷣ᷁質!"#$%&'()*$+,-./01.!2345

酸素輸送᷑ḅᷣ᷁質

Bioinorganic Chemistry!"#$%&'()*$+,-./01.!2345
oxydeoxy!1-superoxideOO

porporFeFe6-coordinate

NN
Fe(II) high-spin

Fe(III) low-spin

HNHN

His87

O

His87

dx2-y2dz2OFe

pordxz dyz

FedxyNN~0.91 ÅHNionic radius~0.69 ÅHNpor

Bioinorganic Chemistry

酸素輸送᷑ḅᷣ᷁質Electronic Structures and Vibrational and Geometrical Propertiesof Dioxygen Derivatives

Bioinorganic Chemistry

酸素輸送᷑ḅᷣ᷁質!"#$%&'()*+,-./01!"#$%&'()

Bioinorganic Chemistry

酸素輸送᷑ḅᷣ᷁質!"!"#$%&'()*+,-./012345678

Bioinorganic Chemistry!"#$%&'()*+,-./01

酸素輸送᷑ḅᷣ᷁質

酸素輸送᷑ḅᷣ᷁質
Model Compounds for Hb and Mb

Bioinorganic Chemistry

Normal Porphyrin Fe(II) Complexes

FeIIP + O 2

FeIIIP–O 2-

FeIIIP–O 2- + FeIIPPFeIII-O 22- -FeIIIP

PFeIII-O 22- -FeIIIP

2 PFeIV =O

PFeIV =O + Fe IIP

PFeIII–O–FeIIIP

Reversible Dioxygen Binding

dead end

picket fence porphyrin
capped porphyrin

酸素輸送᷑ḅᷣ᷁質Bioinorganic Chemistry

Structures of Hemerythrin (Hr)deoxyHrazidometHr
DA
C

FeFeB
His25
N N N

Octamer
108 kDa

His101

Asp106

FeFe

His73

O
Glu58
His54
His77

酸素輸送᷑ḅᷣ᷁質

Bioinorganic Chemistry

Dioxygen Binding Mode of Hemerythrin (Hr)deoxyHr

oxyHr

O2-O2

His101

His54

HN
NN
His25

NH

H

N
H

!!"#$%#$&'()

N

O
Fe

Fe
O
O
Glu58

OO
Asp106

His101

His54

O H

His77

NNH

N

His73

N
H

HN

O
NN

His25

N
H

NH
NO
FeFeOO
Glu58

His77

OO
Asp106

NNH

N

His73NH

酸素輸送᷑ḅᷣ᷁質

Bioinorganic Chemistry

Structural and Spectral Parameters of deoxy- and oxyHr
oxyHr

deoxyHr
HNOO
•
•

NN
N
HHO2(!1-peroxide)•FeIIOOO •• H

NHH
••ON
• IIFeOO

hydrogen bond

NH

NHNO
N ••NN
N
H

N
H

NH

••
N
O(µ-oxo) III
Fe
FeIII
O
OO
O

NH

N
N
N
H

!O-O = 844 cm-1!Fe-O-Fe = 486 (sym), 757 (asym) cm-1

Bioinorganic Chemistry

酸素輸送᷑ḅᷣ᷁質Electronic Structures and Vibrational and Geometrical Propertiesof Dioxygen Derivatives

Bioinorganic Chemistry酸素輸送᷑ḅᷣ᷁質

Model Compounds for Oxyhemerythrin (oxyHr)

酸素輸送᷑ḅᷣ᷁質Bioinorganic Chemistry

Model Compounds for Oxy- and Deoxyhemerythrin (oxy-, deoxyHr)
MeN

III

Fe (ClO 4 )3 + NaOAc + L

L=NN

in H2 O

tacn

NN

Me
FeII (ClO 4 )3 + NaOAc + L

Nin H2 OMe
Me3 tacn

Spontaneous Self-Assembly

NN
N2+NO

N

N

FeIII

FeIII

O O

NOO

N

N

CH3CH3N

IIFeIIFe

monitored by CV

O OOFe(II)Fe(III)
red brown+N

H
OO

CH3CH3N

green yellow[Fe2 (µ-O)(µ-CH 3CO2)2L 2]2+

[Fe2 (µ-OH)(µ-CH3 CO2)2L 2]+

Fe···Fe = 3.12(4) Å

Fe···Fe = 3.32(1) ÅFe-Ooxo = 1.800(3) Å

Fe-OOH = 1.987(8) ÅWieghardt et al, Angew. Chem. Int. Ed. Engl., 1984, 22, 727; 1985, 24, 778
Wieghardt et al, J. Am. Chem. Soc., 1987, 109, 7387

酸素輸送᷑ḅᷣ᷁質

Bioinorganic Chemistry

Model Compound for Dioxygen Binding by Dinuclear Fe CoreN
FeII

NPh

PhCOONaClO

NNOFeIIN

PhO

NNO2N-50°C

N

NO

NO O

colorlessbluish greenPhNNN= HB(3,5-iPr2 pz) 3

HB-iPr

NN
iPr

N

FeIII

OFeIIIO

3Kitajima, Que et al, J. Am. Chem. Soc., 1994, 116, 9071

酸素輸送᷑ḅᷣ᷁質

Bioinorganic Chemistry

Hemocyanin (Hc)

酸素輸送᷑ḅᷣ᷁質

Bioinorganic Chemistry

Active Sites of Hemocyanin
His344
His224

His198

Cu

Cu
His384

3.6~3.7Å
His348
His194deoxyHc (active)!2,!2-peroxide Cu(II)2H
N

HN
N
HN

N

CuI
NNO
O

N

CuI

N
H

deoxyHc (relaxed)

NHN
HN
Cu···Cu = 3.6~3.7 ÅBioinorganic Chemistry

酸素輸送᷑ḅᷣ᷁質

Coordination Behavior of Peroxide Ion on Dinucelar Core

Bioinorganic Chemistry

酸素輸送᷑ḅᷣ᷁質

Dioxygen Binding by Cu(I) Model Compound

酸素輸送᷑ḅᷣ᷁質
Dioxygen Binding by Cu(I) Model Compound

Bioinorganic Chemistry

Bioinorganic Chemistry

FIN