THE METHODS OF L-ARGININE ANALYSIS

Physicochemical and enzymatic methods of quantitative L-arginine estimation are described. A variety of detection procedures for L-arginine analysis have been developed. The majority of the frequently used approaches are marked by poor precision, low sensitivity and selectivity. These methods are time-consuming, expensive and require skilful labor techniques, so it needs to develop novel highly selective and sensitive ones for improvement of L-arginine monitoring in clinical diagnostics and food industry. Experimental data concerning development and testing of effective enzymatic methods of L-arginine determination, including biosensors, are presented. All proposed methods are based on human liver arginase I isolated from the recombinant yeast strain Hansenula polymorpha NCYC-495 pGAP1-HsARG1 (leu2car1 Sc:LEU2). Arginase I (EC 3.5.3.1; L-arginine amidinohydrolase), a key enzyme of the urea cycle, catalyses the conversion of L-arginine to ornithine and urea. An effectiveness of the proposed enzymatic methods for L-arginine assay, as amperometric and potentiometric biosensors so as enzymatic methods with spectrophotometric and fluorometric detection of the product, was demonstrated on the samples of commercial pharmaceuticals. These methods seem to be prospective for L-arginine analyses in food industry (juices and wines) and in medicine, for diagnostics and drug control in blood serum under treatment of cancer malignances. Hence, the proposed L-Arg selective and simple methods would be convenient and useful in the future for routine clinical analysis and food quality control.