Studies of the reaction of NAD-NADASE have been extended on the all tantalum stopped-flow microcalorimeter to 10 degrees C, 25 degrees C, and 37 degrees C confirming the endothermic nature of the reaction by demonstrating the 5-fold increase in activity from 25 degrees C to 10 degrees C with the almost complete loss in activity at 37 degrees C. A new heat capacity measuring microcalorimeter has been developed which is capable of measuring charges of 1 part in one hundred thousand of total heat capacity of phospholipids. A reaction heat of 60 calories/mole was found as they went from multilamellar vesicles to unilamellar vesicles. The total change in heat capacity was 2 to 3% depending on the system.
