Chemotropic Response of the Pollen of <i>Antirrhinum majus</i> to Calcium

Abstract

An improved spectrophotometric method for the determination of lipoxidase activity was developed and applied in studies of the purified enzyme and crude enzyme preparations from leguminous seeds, with linoleic acid solubilized in Tween 20 as the substrate. The optimum pH was found to be 7.0, 6.5, 6.0, and 5.5, for purified soybean lipoxidase and for the crude lipoxidases extracted from gram flour (Ci- cer sp.) soybean meal (Glycibic miax L.), and hy- (lrate(l mung beans (Phaseolhs auircuEs L.), respec- tively. The application of this test illustrates A) that the present method was free from the inherent limita- tions on pH present in the original methods, B) that increasing the amount of detergent, in a fixed concen- tration of fatty substrate, caused inhibition in the enzymatic activity; more pronounced inhibitions occurred when the concentrations of detergent as well as of fatty substrate were increased in equal propor- tions, and C) peroxide formation is proportional to time of reaction and to enzyme concentration.