Biomaterial Database

Determination of phospholipase A2 activity by a colorimetric assay using a pH indicator. 1987

A Lôbo de Araújo, and F Radvanyi

Unité des Venins-Unité associée Pasteur/INSERM no. 285, Département de Physiopathologie Expérimentale, Institut Pasteur, Paris, France.

We have set up an assay of phospholipase A2 by a spectrophotometric method, based on the pH change due to the liberation of fatty acids. Among the pH indicators used, phenol red was found to be one of the most sensitive. The activities of different phospholipases A2 from venom and from porcine pancreas were measured by this assay. The results are comparable to those obtained by the pH stat method. This very simple test is rapid, sensitive and especially useful for assaying numerous samples. For quantitative results in absolute units it must be considered that the pH indicator may inhibit some phospholipases.

UI	MeSH Term	Description	Entries
D008055	Lipids	A generic term for fats and lipoids, the alcohol-ether-soluble constituents of protoplasm, which are insoluble in water. They comprise the fats, fatty oils, essential oils, waxes, phospholipids, glycolipids, sulfolipids, aminolipids, chromolipids (lipochromes), and fatty acids. (Grant & Hackh's Chemical Dictionary, 5th ed)	Lipid
D010637	Phenolsulfonphthalein	Red dye, pH indicator, and diagnostic aid for determination of renal function. It is used also for studies of the gastrointestinal and other systems.	Phenol Red,Sulfonphthal,Sulphental,Sulphonthal
D010740	Phospholipases	A class of enzymes that catalyze the hydrolysis of phosphoglycerides or glycerophosphatidates. EC 3.1.-.	Lecithinases,Lecithinase,Phospholipase
D010741	Phospholipases A	Phospholipases that hydrolyze one of the acyl groups of phosphoglycerides or glycerophosphatidates.
D001979	Bromthymol Blue	A pH sensitive dye that has been used as an indicator in many laboratory reactions.	Dibromothymolsulfonphthalein,Bromothymol Blue,Blue, Bromothymol,Blue, Bromthymol
D003124	Colorimetry	Any technique by which an unknown color is evaluated in terms of standard colors. The technique may be visual, photoelectric, or indirect by means of spectrophotometry. It is used in chemistry and physics. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D054467	Phospholipases A2	Phospholipases that hydrolyze the acyl group attached to the 2-position of PHOSPHOGLYCERIDES.	Lecithinase A2,Phospholipase A2