Browsing by Author "Skinner, Henry A."

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    Enthalpy of interaction between some cationic polypeptides and n-alkyl sulphates in aqueous solution
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1978, 74 (09-12), 1978) Paz-Andrade, Maria I.; Jones, Malcolm N.; Skinner, Henry A.
    The enthalpies of interaction of a homologous series of n-alkyl sulphates with poly(L-lysine)-hydrobromide, poly(L-arginine)hydrochloride and poly(L-histidine)hydrochloride have been measured at 25°C. A linear relationship between the enthalpy of interaction and carbon chain length has been found for alkyl chain lengths above C8. The data support a model based on a stoichiometric interaction between the anionic head group of the n-alkyl sulphates and the cationic side chains of the polypeptides. The results are discussed in relation to the interaction between surfactants and proteins, and lead to the view that a major contribution to the enthalpy of interaction arises from the surfactant–cationic residue interactions, but that there remains an additional contribution from surfactant–apolar aminoacid residue interactions.
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    Enthalpy of Interaction between some Globular Proteins and Sodium n-Dodecyl Sulphate in Aqueous Solution
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1974, 70 (07), 1974) Tipping, Edward; Jones, Malcolm N.; Skinner, Henry A.
    The enthalpy of binding of sodium n-dodecyl sulphate (SDS) to scrum albumin, ovalbumin and ribonuclease A has been measured by microcalorimetry over the temperature range 18.5 to 32.0 C. The amount of SDS bound to the proteins has been measured over a wide range of SDS concentration by equilibrium dialysis. Changes in protein conformation have been monitored by viscometry. The results are consistent with a mechanism in which SDS binds initially to ionic sites on the protein molecules and initiates chain unfolding. At high binding levels the interaction is predominantly of a hydrophobic nature.
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    Microcalorimetric studies: Enthalpies of formation of Cr(PF3)6 and Ni(PF3)4
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1974, 70 (09), 1974) S. Brown, D. Lalage; Connor, Joseph A.; Skinner, Henry A.
    Measurements of the heats of iodination of hexakis(trifluorophosphine)chromium(0) and of tetrakis(trifluorophosphine)nickel(0) were carried out by high temperature microcalorimetry. Standard enthalpies of formation were derived: ΔH°f(Ni(PF3)4, liq)=–961.9 ± 3 kcal mol–1(–4025 ± 12 kJ mol–1), ΔH°f(Cr(PF3)6, c)=–1446.4 ± 4 kcal mol–1(–6052 ± 17 kJ mol–1). The mean bond dissociation energies, D(Ni—PF3) and D(Cr—PF3) were evaluated as 35.2 ± 0.8 and 25.5 ± 1 kcal mol–1 respectively; these values compare very closely with the values D(Ni—CO) and D(Cr—CO) in Ni(CO)4 and Cr(CO)6.