Journal of clinical chemistry and clinical biochemistry. Zeitschrift fur klinische Chemie und klinische Biochemie 1985-07-01

A continuous method for the determination of leucine aminopeptidase in human serum with L-leucinamide as substrate.

J C Hafkenscheid, B E Kohler

Index: J. Clin. Chem. Clin. Biochem. 23(7) , 393-8, (1985)

Full Text: HTML

Abstract

A continuous procedure for the determination of leucine aminopeptidase is described. L-leucinamide is used as substrate and the liberated ammonia is determined with the glutamate dehydrogenase reaction. The enzyme is Mn2+-activated and 30 mumol/l MnCl2 is necessary for an optimal activity measurement. Influence of buffer type, buffer concentration and pH are reported together with the apparent Km values of leucine aminopeptidase for L-leucinamide and of glutamate dehydrogenase for 2-oxoglutarate. Amastatin, a potent inhibitor, inhibits the reaction of leucine aminopeptidase completely, whereas it has no inhibitory effect on the reaction with glutamate dehydrogenase. The normal reference interval for leucine aminopeptidase is 12-65 U/l at 37 degrees C. The properties of the enzyme are discussed.

Related Compounds

  • H-Leu-NH2.HCl
  • H-DL-Leu-NH2.H...

Related Articles:

L-Leucinamide hydrogensquarate: spectroscopic and structural elucidation.

2009-10-01

[Amino Acids 37(4) , 693-701, (2009)]

Rotational spectra and computational analysis of two conformers of leucinamide.

2011-09-01

[J. Phys. Chem. A 115 , 9676-9681, (2011)]

Formation of diastereomeric derivatives of 2-arylpropionic acids using L-leucinamide: lack of generality.

[J. Chromatogr. A. 431(1) , 228-30, (1988)]

Determination of the enantiomers of ketoprofen in blood plasma by ion-pair extraction and high-performance liquid chromatography of leucinamide derivatives.

[J. Chromatogr. A. 414 , 465, (1987)]

Enzymatic peptide synthesis in organic media: a comparative study of water-miscible and water-immiscible solvent systems.

1990-09-01

[J. Biotechnol. 15(4) , 323-38, (1990)]

More Articles...