No abstract

A new technique with controlled interface generation allows separation and quantitation of enzyme inactivation by both solvent/aqueous interface and dissolved solvent. This has now been used in n-butanol, isopropylether, 2-octanone, n-hexane, n-butylbenzene, and n-tridecane. Ribonuclease was stable with all the solvent/aqueous interfaces studied. Chymotrypsin was mainly inactivated by the more hydrophobic solvent/aqueous interfaces, whereas lipase was only inactivated by the less hydrophobic solvent/aqueous interfaces. Urease was inactivated by some interfaces, but not all, without an obvious trend. Thus, the commonly expected simple relationship with solvent polarity (e.g., log P) does not apply when interfacial inactivation is determined specifically. Greater dissolved solvent inactivation occurred with the more polar solvents, though only a general trend was apparent with log P. A better correlation was noted with the Hilde-brand solubility parameter. Interfacial effects are discussed with reference to enzyme molecular weight, denaturation temperature, hydrophobicity, and adiabatic compressibility.

No abstract

No abstract

Sesame seeds are an important source of edible oil and protein. Studies were made on protein solubility of defatted sesame seed meal in aqueous solution over various pHs or in various salt solutions. Maximum solubility was found in alkaline solution, and the proteins were almost insoluble at acid solution. The solubility of protein in NaC1 or CaC12 solution was increased upon increasing the salt concentrations up to 1 M. In Na2SO3 or Na2HPO 4 solution, the solubility of protein was higher at lower salt concentrations but decreased at higher salt concentrations at pH 8. Extractable sesame seed proteins in salt solution separated into seven fractions electrophoretically (sodium dodecyl sulfate-polyacrytamide gel electrophoresis). The mol wt of the seven fractions were 51,