A glucose dehydrogenase for the determination of glucose concentrations in body fluidsThe isolation of glucose dehydrogenase from Bacillus megaterium M 1286 is outlined. Data on the specificity of the enzyme towards carbohydrates are given. A specific method for glucose determination using this enzyme was developed. Methods and results of four variants of this glucose determination are presented: End point determination in the UV range, determination with formazan as reaction product, kinetic determination in the UV range, and continuous flow analysis in the UV range (AutoAnalyzer method).

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Summary:The influence of colipase on the turbidinietric measurement of the catalytic activity of pure human pancreatic lipase (EC 3.1.1.3) and of sera from pancreatitis patients was studied. A deoxycholate-stabilized triolein emulsion served äs Substrate. It was found that the activity of the pure, colipase-free lipase is strongly inhibited by deoxycholate, and can be blocked completely if normal serum, pure human albumin, or the globulin fraction of normal serum is present. The Inhibition by serum is competitive. This finding largely excludes the existence öf ä specific lipase Inhibitor in human serum and explains the non-linear response of activity to the amount of seruni added, a frequently observed problem with various turbidimetric lipase methods. A high molar excess of colipase (>250-fold) completely abolishes the Inhibition of lipase, irrespective of the inhibitory factor studied. Sera of pancreatitis patients, when measured turbidimetrically without addition of colipase, exhibit elevated lipase activity only if they contain colipase. However, the activity measured is not a function of the serum lipase coneentration alone but of the molar ratio of colipase to lipase. Since this ratio varies considerably and is usually too low to ensufe complete activation of lipase, erroneously low or even false negative results are obtained. For this reason it is strongly recommended that an excess of colipase is used in turbidimetric lipase assays. It therefore also appears important to study the influence of the serum colipase level on non-turbidimetric lipase methods. Einfluß von Colipase auf die turbidimetrische Aktivitätsbestimmung von Pankreaslipase

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