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Bioscience Methods
BM 2011, Vol.2, No.4, 21-30
http://bm.sophiapublisher.com
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Figure 1 Outline of the experimental steps involved in the extraction and purification of jellyfish mucins
Note: Mature
Catostylus mosaicus
jellyfish showing bell and tentacles (permission to use from OceanwideImage.com, NSW,
Australia). Animals with a bell diameter of over 23 cm weigh in excess of three kilograms, with 60% of the weight as tentacles; A:
Bell, umbrella-shaped body of jellyfish; B: purification of bell mucin; C: Purification of exudate mucin
was checked by SDS-PAGE. Based on the SDS-PAGE
and the Alcian blue staining profiles of the trypsin
digested exudate (Figure 2, lane D), the presence of a
mucin-like protein could not be confirmed despite the
extract’s consistency. No attempt was made to further
characterize this material. It is possible that non-
proteinacious material could have been responsible for
the mucin-like physical properties of the exudate.
The protein concentrations in the bell mucin and
exudate mucin extracts were initially determined by
using the BCA protein assay with bovine serum
albumin as the standard (Pierce Biotechnology IL.,
USA). This yielded figures of 2.5 mg/jellyfish and
23 mg/jellyfish, respectively. However, this assay may
have underestimated the true protein concentration of
purified mucins due to their low Trp, Tyr and Cys
amino acid contents (Chen et al., 2008). To better
determine the yield of mucin, the bell mucin and the
exudate mucin were extensively dialyzed against
distilled water and a standard volume of each was
freeze-dried and their weights measured. These
estimates indicated that the yield of purified bell
mucin was 72 mg/jellyfish or 0.008% of the bell tissue
wet weight. The yield of exudate mucin was 391 mg/
jellyfish or 0.09% of the total jellyfish wet weight.
1.2 Amino acid and monosaccharide compositions
Analysis of the monosaccharide composition of the
C.
mosaicus
bell mucin revealed very high carbohy-
drate content (>50% of the dry weight) with N-acety-
lgalactosamine (GalNAc), galactose (Gal) and N-ace-
tylglucosamine (GlcNAc) as major constituents, and
minor amounts of mannose and sialic acid (Table 1).
The prevalence of GalNAc, in particular, is consistent
with extensive O-linked glycosylation. The excess of
GalNAc compared with other monosaccharides indicates