Objectives:
Although we work on bacterial polysaccharides our goals are general to all
filamentous polymers. They are
- developing methods for obtaining intramolecular distances from nmr and
fiber diffraction data
- using these data to discriminate between competing molecular models
- developing methods of comparing local structure in solution to solid-state structure.
Samples:
Bacterial Polysaccharides are:
- High Molecular Weight- 10**5 - 10 ** 7
- Usually charged polymers whose
- Structures may be
- Linear Homopolymer such as the -6 linked polymer of
alpha D mannose -1 -phosphate in type A Neisseria
meningitidis (I)
- or linear poly oligosaccharides of di-, tri, or tetra- saccharides i.e.
polysacccharide from S3, S1, and S8 Streptococcus pneumoniae.
Chemical structure of S1, a polymer of -[3) 2-acetamido-4-amino-2,4,6 trideoxy-alpha-D- galactopyranose (1-4) galactpyrosyluronic acid (1-3) galactopyranosyluroic acid (1-] (II)
- periodically branched structures such as that of xanthan gum from
Xanthomonas campestris(III)
or the poly pentasaccharide from S. pneumoniae type S5 (IV)
Analysis:
After assigning ALL peaks from COSY, TOCSY and HETCOR (HMQC, HMBC) type experiments, we measure couplings
Large J-3 couplings imply transconformers.
compare the NOESY AND COSY spectra to identify short,
through space interactions
<h3>Regularly branched as in xanthan gum, Streptococcal S5 etc
- The X-ray data can also be rich as shown by these examples for Xanthan gum and the pneumococcal S5 polymers.
Here distance constraints are implicit in the layer line spacing and helix symmetry
Finally a list of short interactions is developed for comparison with results on phi-psi maps or
for use in constraint equations
- developing methods for obtaining intramolecular distances from nmr and fiber diffraction data
- using these data to discriminate between competing molecular models
- developing methods of comparing local structure in solution to solid-state structure.
Samples:
Bacterial Polysaccharides are:
- High Molecular Weight- 10**5 - 10 ** 7
- Usually charged polymers whose
- Structures may be
- Linear Homopolymer such as the -6 linked polymer of
alpha D mannose -1 -phosphate in type A Neisseria
meningitidis (I)
- or linear poly oligosaccharides of di-, tri, or tetra- saccharides i.e. polysacccharide from S3, S1, and S8 Streptococcus pneumoniae.
Chemical structure of S1, a polymer of -[3) 2-acetamido-4-amino-2,4,6 trideoxy-alpha-D- galactopyranose (1-4) galactpyrosyluronic acid (1-3) galactopyranosyluroic acid (1-] (II)
- periodically branched structures such as that of xanthan gum from Xanthomonas campestris(III)
or the poly pentasaccharide from S. pneumoniae type S5 (IV)
Analysis:
After assigning ALL peaks from COSY, TOCSY and HETCOR (HMQC, HMBC) type experiments, we measure couplings
Large J-3 couplings imply transconformers.
compare the NOESY AND COSY spectra to identify short, through space interactions
<h3>Regularly branched as in xanthan gum, Streptococcal S5 etc- The X-ray data can also be rich as shown by these examples for Xanthan gum and the pneumococcal S5 polymers.
- or linear poly oligosaccharides of di-, tri, or tetra- saccharides i.e. polysacccharide from S3, S1, and S8 Streptococcus pneumoniae.