Jornal de Biomarcadores Moleculares e Diagnóstico

A novel Enzyme Inhibition Assay for Screening of Type 1 Diabetes Mellitus

Abstract

Manoochehr Messripour

Glutamate decarboxylase (GAD) antibody has been found in patients with recent-onset insulin dependent diabetes mellitus (IDDM). Several analytical methods are described for detection and quantitation of anti-GAD antibodies whereas the inhibition of the enzyme activity by anti-enzyme antibody is given little attention. In this study a quenching fluorimetric method based on changes of fluorescence intensities upon addition antiserum into the enzyme/substrate medium is described. The activity of the purified rat brain GAD was measured by both manometeric and fluorimeteric methods in the presence of serum samples from IDDM patients (n=21) or non diabetic subjects (n=21). Significant differences between the patients and control groups were observed using both methods. However, high degree of fluorescence sensitivity of fluorimetric technique allows for less error, less time and satisfactory useful and economical for screening of IDDM in the large populations.