TY - JOUR
T1 - Thermotropic Behavior of Glycosphingolipids in Aqueous Dispersions
AU - Maggio, Bruno
AU - Ariga, Toshio
AU - Sturtevant, Julian M.
AU - Yu, Robert K.
PY - 1985/2/1
Y1 - 1985/2/1
N2 - The thermotropic behavior of 20 chemically related glycosphingolipids (GSLs) of high purity, containing neutral and anionic carbohydrate residues in their oligosaccharide chains, was studied by high-sensitivity differential scanning calorimetry. In general, the polar head group of GSLs appears to be one of the major determinants of their phase behavior. Compared to phospholipids, the presence of the carbohydrate rather than the phosphorylcholine moiety in the polar head group and a sphingosine base in the hydrocarbon portion of GSLs reduces the effect on the transition temperature (Tm) brought about by increasing the number of methylene groups in the amide-linked fatty acyl chains. For simple neutral GSLs, the Tm's were 20-40 °C higher than those of phospholipids with comparable hydrocarbon chains. As the oligosaccharide chain of GSLs becomes more complex, the excess heat capacity, Tm, enthalpy (ΔHcal), and entropy of the transition decrease proportionally to the number of carbohydrate residues present in the polar head group. The Tm and ΔHCal for anionic GSLs were 16-25 °C and 1-3 kcal mol-1 lower than those of neutral GSLs with comparable oligosaccharide chains. A linear dependence of ΔHcal with Tm was found. However, the slopes of these plots were different for neutral and for anionic GSLs, suggesting different types of intermolecular organizations for the two. The Tm and ΔHcal were linearly dependent on the molecular area of both neutral and anionic GSLs; this indicated that the influence of the complexity of the polar head group in GSLs for establishing the thermodynamic behavior may be mediated by the intermolecular spacings.
AB - The thermotropic behavior of 20 chemically related glycosphingolipids (GSLs) of high purity, containing neutral and anionic carbohydrate residues in their oligosaccharide chains, was studied by high-sensitivity differential scanning calorimetry. In general, the polar head group of GSLs appears to be one of the major determinants of their phase behavior. Compared to phospholipids, the presence of the carbohydrate rather than the phosphorylcholine moiety in the polar head group and a sphingosine base in the hydrocarbon portion of GSLs reduces the effect on the transition temperature (Tm) brought about by increasing the number of methylene groups in the amide-linked fatty acyl chains. For simple neutral GSLs, the Tm's were 20-40 °C higher than those of phospholipids with comparable hydrocarbon chains. As the oligosaccharide chain of GSLs becomes more complex, the excess heat capacity, Tm, enthalpy (ΔHcal), and entropy of the transition decrease proportionally to the number of carbohydrate residues present in the polar head group. The Tm and ΔHCal for anionic GSLs were 16-25 °C and 1-3 kcal mol-1 lower than those of neutral GSLs with comparable oligosaccharide chains. A linear dependence of ΔHcal with Tm was found. However, the slopes of these plots were different for neutral and for anionic GSLs, suggesting different types of intermolecular organizations for the two. The Tm and ΔHcal were linearly dependent on the molecular area of both neutral and anionic GSLs; this indicated that the influence of the complexity of the polar head group in GSLs for establishing the thermodynamic behavior may be mediated by the intermolecular spacings.
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U2 - 10.1021/bi00326a003
DO - 10.1021/bi00326a003
M3 - Article
C2 - 4096890
AN - SCOPUS:0022432688
SN - 0006-2960
VL - 24
SP - 1084
EP - 1092
JO - Biochemistry
JF - Biochemistry
IS - 5
ER -