Dosage automatique de la l-leucinamidase alcaline du sérum humain un test de cytolyse hépatique plus sensible que les transaminases?

Plaquet, R; Ledeme, N; Vincent-Fiquet, O; Biserte, G

doi:10.1016/0009-8981(73)90107-1

Cited by 6 publications

(4 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Plaquet et al (81) found two forms of leucinamidase activity in serum with different pH optima. The enzyme with a neutral pH optimum was inhibited by Mg 2+ and was predominant in normal sera.…”

Section: Substrates and Methods Of Analysis Of Aminopeptidases From Smentioning

confidence: 99%

See 1 more Smart Citation

Human Aminopeptidases: A Review of the Literature

Sanderink¹,

Artur²,

Siest³

1988

Clinical Chemistry and Laboratory Medicine

View full text Add to dashboard Cite

Summary:The aminopeptidases constitute a group of enzymes with closely related activities. In clinical chemistry the analysis of the aminopeptidases and of their multiple forms in serum has for a long time been hindered by considerable confusion concerning their identification, and by a lack of characterization. This is in part due to the often large, and sometimes overlapping substrate specificities of the aminopeptidases. This paper reviews the biochemical properties of the different aminopeptidases, the specificities of the assays used for their analysis in serum, some aspects of their multiple forms -which are especially known to occur for alanine äminopeptidase (EC 3.4.11.2) -and the importance of the determination of aminopeptidases and their multiple forms in clinical chemistry.

show abstract

Section: Substrates and Methods Of Analysis Of Aminopeptidases From Smentioning

confidence: 99%

“…Plaquet et al (81) eliminated the neutral activity by performing the reaction at pH 9 in the presence of Mg 2H~ ions, which activates leucine aminopeptidase and inhibits alanine aminopeptidase.…”

Section: Substrates and Methods Of Analysis Of Aminopeptidases From Smentioning

confidence: 99%

Human Aminopeptidases: A Review of the Literature

Sanderink¹,

Artur²,

Siest³

1988

Clinical Chemistry and Laboratory Medicine

View full text Add to dashboard Cite

show abstract

“…Plaquet et al (6) described in normal and pathological human sera two enzymes, which are able to split Lleucinamide. The "alkaline enzyme" has a pH optimum of 9.0 and is activated by Mg 2+ ions, while the second enzyme ("neutral enzyme"), has an optimal activity at pH 7.8 and is inhibited by Mg 2+ ions.…”

Section: Resultsmentioning

confidence: 99%

“…formed from L-leucinämide after hydrolysis is deter-Leucine aminopeptidase (ot-aminoacyl-peptide mined by paper chromatography (5) or the liberated hydrolase (cytosol); EC 3.4.114) is a zinc-metallö-ammonia is rneasured according to Berthelot (6,7) or enzyme, which oceurs in tissues and body fluids of by titration (8). Unti'l now no continuous monitoring all organisms.…”

Section: Introductionmentioning

confidence: 99%

A Continuous Method for the Determination of Leucine Aminopeptidase in Human Serum with L-Leucinamide as Substrate

Hafkenscheid¹,

Kohler²

1985

Clinical Chemistry and Laboratory Medicine

View full text Add to dashboard Cite

A continuous procedure for the determination of leucine aminopeptidase is described. L-leucinamide is used äs Substrate and the liberated ammonia is determined with the glutamate dehydrogenase reaction. The enzyme is Mn 2 +-activated and 30 / MnCl 2 is necessary for an optimal activity measurement. Influence of buffer type, buffer concentration and pH are reported together with the apparent K m values of leucine aminopeptidase for L-leucinamide and of glutamate dehydrogenase for 2-oxoglutarate. Amastatin, a potent inhibitor, iiihibits 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 °C. The properties of the enzyme are discussed. Eine kontinuierliche Methode zur Bestimmung von Leucinaminopeptidase in menschlichem SerumZusammenfassung: Es wurde ein kontinuierliches Verfahren zur Bestimmung von Leucinaminopeptidase mit L-Leucinamid als Substrat untersucht. Das freigesetzte Ammoniak wird mit der Glutamatdehydrogenase-Reaktion bestimmt. Das Enzym wird aktiviert von Mn 2 + und 30 / von MnCl 2 ist für eine optimale Aktivität erforderlich. Der Einfluß von Art des Puffer, Pufferkonzentration und pH wird zusammen mit dem scheinbaren # m -Wert von Leucinaminopeptidase für L-Leucinamid und von Glutamatdehydrogenase für 2-Oxoglutarat beschrieben. Amastatin hemmt Leucinaminopeptidase vollständig, während es keine hemmende Wirkung auf die Glütamatdehydrogenase-Reaktion hat. Der Referenzbereich beträgt 12-65 U/l bei 37 °C. Die Eigenschaften des Enzyms werden diskutiert.

show abstract