Influence of charged groups on the conformational stability of succinoglycan in dilute aqueous solution.
Viscosity, optical activity, and differential scanning calorimetry data clearly point out that partial and/or total removal of charged substituent groups, i.e. succinate and pyruvyl residues, from succinoglycan lead to water soluble derivatives exhibiting a higher stability order----disorder conformational changes with respect to the native polysaccharide. The new succinoglycan derivatives also exhibit very little, if any, hysteresis upon 'renaturation' (cooling) as opposed to the case of the parent polymer. The absence of ionized groups is thus beneficial, thermodynamically and kinetically, to the attainment in dilute aqueous solution of an ordered conformation by the uncharged succinoglycan backbone, as allowed by the regular enchainment of its constituent sugar residues.
Fidanza
M
M
Department of Chemistry, University La Sapienza, Rome, Italy.
Dentini
M
M
Crescenzi
V
V
Del Vecchio
P
P
D002152:Calorimetry, Differential Scanning; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002942:Circular Dichroism; D007700:Kinetics; D008969:Molecular Sequence Data; D011135:Polysaccharides, Bacterial / Q000737:chemistry*; D012996:Solutions; D013696:Temperature; D013816:Thermodynamics; D014783:Viscosity
D011135:Polysaccharides, Bacterial; D012996:Solutions; C056779:succinoglycan