| dc.description.abstract |
A water-soluble high-molecular neutral polysaccharide (NP) was isolated from the eggs
of the sea urchin Tripneustes gratilla. The formation of glucose only upon the treatment
of NP by amyloglucosidase and the value of its optical rotation [α]D +233.5 (c 0.2, water)
confirmed its belonging to the family of α-D-glucans. According to the results of NMR
spectroscopy and methylation analysis, the chains of NP are built up of non-reducing
terminal, 4-linked and 4,6-disubstituted glucose residues at a ratio of 1:8:1. A branched
structure with an average linear chain length of about five glucose residues was calculated
from the spectrum of iodine complex. Contrary to the previously published structure of
branched α-D-glucan from the sea urchin Strongylocentrotus nudus bearing single glucose
units as branches, the polysaccharide NP contains oligosaccharide branches at position
6, which was confirmed by NMR data. Hence, NP has a glycogen-like structure with a
rather high degree of branching, which markedly exceeds that of usual mammalian or
fungal glycogens |
vi,en |