maenas (intertidal zone) and Segonzacia mesatlantica - Station ...

172 Current Protein and Peptide Science, 2008, Vol. 9, No. 2 Bruneaux et al.
(a)
4000
Lt
y = 1,807x - 2318
R 2 = 0,8485
MALLS mass (kDa)
3800
3600
Rp
Md
Am
Ms
Am
Ac
Ap
Pg
Pp
Lt
y = 1,0576x + 46,043
R 2 = 0,9582
3400
Tj
y = 1,1252x - 304,64
R 2 = 0,9971
Ev
3200
3200 3400 3600 3800
Model mass (kDa)
4000
(b)
16
Group 3
14
∆(MALLS mass – model mass) %
12
10
8
6
4
2
(12)
Group 1
(6)
Group 2
0
Fig. (8). Self-association properties of AmHb.
Self-association properties of AmHb followed by MALLS detector
during the elution on a gel exclusion column (Superose 6-C). The
solid curve represents the refractive index (RI) profile overlaid with
the dotted curve which represents the light scattering profil at 90°
(LS), versus the retention time. The red curves set for AmHb after
dissociation and the blue curves set for AmHb after reassociation.
(a) AmHb immediately after exposure in 0.1 M Tris-HCl buffer pH
8.0 and immediately reassociated. (b) AmHb dissociated immediately
after exposure in 0.1 M Tris-HCl buffer pH 9.0 and immediately
reassociated. (c) AmHb dissociated in 0.1 M Tris-HCl buffer
pH 8.0 after 1 hour and reassociated. The percentages of HBL are
indicated after dissociation (red) and after reassociation (blue).
They are calculated from the integration of HPLC chromatogram at
414 nm.
7. INVESTIGATING RESPIRATORY PIGMENT DI-
VERSITY AMONG PHYLA
7.1. HBL-Hb Diversity in Annelids
Annelid HBL-Hbs share the same global quaternary
structure, as demonstrated by the typical shape observed in
electron microscopy for these molecules. However, precise
structural studies and three-dimensional reconstructions of
their volume in the recent years shed light on high diversity
among the different groups. Table 1 presents available data
- 2
Ev Cm Tj Ac Am Cm Lt Rp Ms Pp Am Pg Ap Md Lt
Species
Fig. (9). Comparison between native mass (MALLS) and model
mass (ESI-MS).
Comparison between measured native mass determined by MALLS
and model mass calculated from ESI-MS data. The masses are
taken from in Table 1. (a) Plot of MALLS mass versus model mass
for annelid HBL-Hbs. The dashed line corresponds to equality between
MALLS and model masses. The three linear regression displayed
were performed on each group mentioned in (b). (b) Relative
difference between MALLS and model masses. The species are
sorted by increasing difference value. The values for Carcinus
maenas dodecamers (12) and hexamers (6) are added for comparison.
Three groups were considered based on the difference values.
Ac, Alvinella caudata; Am, Arenicola marina; Ap, Alvinella pompejana;
Cm, Carcinus maenas; Ev, Eudistylia vancouverii; Lt,
Lumbricus terrestris; Md, Macrobdella decora; Ms, Marphysa sp.;
Pg, Paralvinella grasslei; Pp, Paralvinella palmiformis; Rp, Riftia
pachyptila.
concerning subunit composition of HBL-Hbs from different
species.
Denaturing ESI-MS is very useful for subunit diversity
investigation. It is worthwhile to note that the MS analyses
were often performed on a pool from several individuals.
Hence the observed diversity is rather representative of the
pool and single individuals could exhibit lesser diversity. All
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