Structural and immunological comparisons of gum arabic and gum mesquite and the analysis of ring forms of reducing monosaccharides and the reducing units of oligosaccharides
General Material Designation
[Thesis]
First Statement of Responsibility
F. J. Miskiel
Subsequent Statement of Responsibility
J. H. Pazur
.PUBLICATION, DISTRIBUTION, ETC
Name of Publisher, Distributor, etc.
The Pennsylvania State University
Date of Publication, Distribution, etc.
1990
PHYSICAL DESCRIPTION
Specific Material Designation and Extent of Item
161
DISSERTATION (THESIS) NOTE
Dissertation or thesis details and type of degree
Ph.D.
Body granting the degree
The Pennsylvania State University
Text preceding or following the note
1990
SUMMARY OR ABSTRACT
Text of Note
Antibodies against gum arabic and gum mesquite were purified by affinity chromatography. Structural features were determined for the gums by methylation, GLC, and mass spectrometry and identification of hydrolytic products. The antibodies have been characterized by ultracentrifugation, isoelectric focusing, agar diffusion, and hapten inhibition experiments. Some interesting cross-reactivities and structural similarities between the two gums were observed. It was found that any modification of the gums which altered the uronic acid moieties destroys antigenicity and that gum arabic induced production of two sets of antibodies while gum mesquite induced production of only one antibody type. The structure of the two immunodeterminant groups in gum arabic were determined to be usd\alphausd-L-arabinofuranosyl-(1 usd\tousd 4)-D-galactose and usd\betausd-D-glucuronopyranosyl-(1 usd\tousd 6)-D-galactose while the immunodeterminant of gum mesquite was determined to be 4-methyl-usd\betausd-D-glucuronopyranosyl-(1 usd\tousd 6)-D-galactose. The cross-reactivity of the two antibodies is due to the ability of both gum antibodies to recognize the usd\betausd-D-glucuronopyranosyl-(1 usd\tousd 6)-D-galactose grouping regardless of the methyl substitution at position 4 in the uronic acid of gum mesquite. Further characterization of the anti-gum mesquite antibody preparation showed it to be highly restricted in structural types and homogeneous with respect to molecular weight and immunoglobulin class. The purified antibody preparation consisted of six isoantibodies recognizing the same immunodeterminant group. The titre of the antibodies was high, averaging 13 mg protein per ml serum. During structural analysis of the gums, it was found that the combined techniques of methylation, gas-liquid chromatography, and mass spectrometry could yield information on the furanose and pyranose ring transformation of reducing monosaccharides and the reducing unit of oligosaccharides. In the dimethyl sulfoxide solvent used in the methylation procedure, the oligosaccharides with arabinose or galactose at the reducing ends occurred as arabinofuranose or galactofuranose to the extent of 55 to 65%, respectively. An interesting observation is the finding that the reducing units in oligosaccharides in which the glycosyl unit is linked to the reducing end by usd\alphausd-glycosidic linkages occur in a higher percentage in the furanose ring form than those linked by usd\betausd-linkages.