Biology Reference
In-Depth Information
a high-spin complex, respectively. NO can also bind to the ferric protein.
The optical signatures of the various species are summarized in
Table 6.1
.
In addition to these states, haemoglobin and certain variants of haemoglobin
and myoglobin can undergo aberrant ligation of the haem iron by a protein
side chain on the distal side (
Culbertson & Olson, 2010; Rachmilewitz &
Harari, 1972; Rachmilewitz & White, 1973; Sugawara et al., 2003
). These
Table 6.1 Optical properties of sperm whale myoglobin
l
max
(nm)
(«,mM
1
cm
1
)
Conditions
Ferrous state
Soret
Visible
d
g
b
a
pH 7, 20
C
Mb (deoxy)
434
(115)
556
(11.8)
pH 7, 20
C
MbO
2
(oxy)
348
(26)
418
(128)
543
(13.6)
581
(14.6)
pH 7, 4
C
MbCO (carbonmonoxy)
345
(26.9)
422
(201)
540
(14)
576
(12.1)
pH 7, 4
C
MbNO (nitrosyl)
420
(133)
548
(11.9)
580
(10.7)
Ferric state
Soret
Visible
d
g
pH 6, 25
C
Mb H
2
O
(aquomet)
a
409
(157)
505
(9.5)
635
(3.6)
Mb (OH
) (hydroxymet)
pH 11.5, 25
C
358
(33.5)
414
(97.2)
542
(9.48)
582
(9.10)
Mb (CN
) (cyanomet)
pH 7, 25
C
359
(29.4)
424
(113)
541
(10.4)
Mb (N
3
) (azidomet)
422
(116)
542
(10.3)
574
(8)
pH 7, 4
C
Mb (F
) (fluorimet)
pH 7, 4
C
406
(133)
489
(8.8)
606
(8.5)
pH 7, 4
C
Mb NO
420
(149)
532
(11.5)
573
(12.5)
a
The p
K
a
of the aquomet-hydroxymet transition is
9.
Taken from
Antonini and Brunori (1971)
and
Dawson, Kadkhodayan, Zhuang, and Sono (1992)
.
