Abstract
A secreted phospholipase A2 (PLA2) has been discovered. It is produced by Streptomyces violaceoruber A-2688 and is the first PLA2 identified in prokaryote. In this study, the enzyme is demonstrated to be useful in measuring the content of calcium(II) ion in fluid, such as plasma and serum. Two methods were established for the measurement: one measures the increase of fluorescence intensity liberated as a result of the hydrolysis of phosphatidylcholine carrying a fluorescence-tag using the bacterial PLA2; the other, a spectrophotometric method, is based on the increase in 500-nm absorbance due to quinoneimine-dye formed as a result of the hydrolysis of lecithin by PLA2. These enzymatic measurements are novel methods for the determination of calcium(II) ion content.
