Thermodynamics of fatty acid degradation.

In this communication, the correlation of some thermodynamic properties of structurally similar biological compounds with items such as the number of carbon atoms or the number of its characteristic groups, such as phosphates, was applied to enzyme thermodynamics, to advance the thermodynamics of fatty acid degradation. It was shown that these concepts apply equally well for all three major thermodynamic functions: Gibbs energy of formation, enthalpy of formation, and entropy of formation. First, the standard transformed Gibbs energies of formation, Δ(f)G'(o), were calculated for the major portion of saturated fatty acids at 25 °C and pH 5, pH 7, and pH 9.

Optimization of conditions for acid protease partitioning and purification in aqueous two-phase systems using response surface methodology.

Aspergillopepsin I, an acid protease, was purified using an aqueous two-phase system that comprised various combinations of polyethylene glycol (PEG), NaH2PO4 and NaCl. Partition of the enzyme depended upon the molecular mass of the PEG and the presence of NaCl. With PEG 1500, 4000 and 6000, the partition coefficients were increased by 1,500-, 1,800- and 560-fold compared to values without NaCl.

Deriving the rate equations for product inhibition patterns in bisubstrate enzyme reactions.

In this work, the full rate equations for 17 completely reversible bisubstrate enzyme kinetic mechanisms, with two substrates in the forward and two in the reverse direction, have been presented; among these are rapid equilibrium, steady-state, and mixed steady-state and rapid equilibrium mechanisms. From each rate equation eight product inhibition equations were derived, four for the forward and four for the reverse direction. All the corresponding product inhibition equations were derived in full; thus a total of 17 x 8 = 136 equations, were presented.

Glucose oxidase from Aspergillus niger: the mechanism of action with molecular oxygen, quinones, and one-electron acceptors.

Glucose oxidase from the mold Aspergillus niger (EC 1.1.3.

Inactivation of cytochrome-c with glucose oxidase.

A novel reaction of cytochrome-c from the horse heart with the enzyme glucose oxidase from Aspergillus niger (EC 1.1.3.