A calorimetric study of phosphocholine membranes mixed with desmopressin and its diacylated prodrug derivative (DPP).
The influence of the water-soluble peptide, desmopressin (DDAVP) and its dipalmitoylated prodrug derivative (DPP) on the thermal behaviour of three different saturated phosphatidylcholine lipid membranes was investigated by differential scanning calorimetry. For lipid membranes composed of dimyristoyl, dipalmitoyl and distearoyl phosphatidylcholines the addition of DDAVP at concentrations of up to 10 mol% resulted in an insignificant change in the thermodynamic phase behaviour. In contrast, the dipalmitoylated DPP prodrug caused major changes on the lipid membrane phase behaviour manifested as a drastic decrease in the heat capacity peak height and a concomitant broadening of the main phase transition as well as a decrease in the transition enthalpy. In addition, the main phase transition temperature was slightly decreased and the pre-transition of the three phosphatidylcholines was abolished when DPP was present.
Pedersen
Tina B
TB
Department of Pharmaceutics, The Royal Danish School of Pharmacy, Universitetsparken 2, DK-2100 Copenhagen, Denmark.
Frokjaer
Sven
S
Mouritsen
Ole G
OG
Jørgensen
Kent
K
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry; D002152:Calorimetry, Differential Scanning / Q000379:methods; D003894:Deamino Arginine Vasopressin / Q000737:chemistry*; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry; D008567:Membranes, Artificial; D010713:Phosphatidylcholines / Q000737:chemistry; D010767:Phosphorylcholine / Q000737:chemistry*; D011355:Prodrugs / Q000737:chemistry*; D013816:Thermodynamics
D008051:Lipid Bilayers; D008567:Membranes, Artificial; D010713:Phosphatidylcholines; D011355:Prodrugs; D010767:Phosphorylcholine; D015060:1,2-Dipalmitoylphosphatidylcholine; C010942:1,2-distearoyllecithin; D003894:Deamino Arginine Vasopressin; D004134:Dimyristoylphosphatidylcholine