An enzyme immunoassay of human polymorphonuclear leukocyte cathepsin G.
An enzyme immunoassay has been developed for the quantitation of human polymorphonuclear leukocyte cathepsin G. The assay had a linear relationship over the range 0.23-4.7 nmol/l (6-125 ug/l) and a detection limit of 0.23 nmol/l (6 ug/l). Recovery in citrated plasma only occurred when the concentration was higher than 4.0 umol/l (110 mg/l). This effect could be overcome by diluting the plasma before adding the proteinase or by inactivating the proteinase before diluting it with plasma. The failure to detect cathepsin G in plasma was due to the plasma inhibitor alpha-2-macroglobulin masking the antigenic sites of the proteinase. Samples from several types of leukemia showed no detectable cathepsin G even when the total myeloid count was up to ten times the normal.
Turkington
P T
PT
Department of Medical Laboratory Technology, Kuwait University, Sulaibikhat.
D056649:Cathepsin G; D002403:Cathepsins / Q000032:analysis* / Q000037:antagonists & inhibitors; D004789:Enzyme Activation; D006801:Humans; D007124:Immunoenzyme Techniques; D007938:Leukemia / Q000201:enzymology; D009363:Neoplasm Proteins / Q000032:analysis; D009504:Neutrophils / Q000201:enzymology*; D012680:Sensitivity and Specificity; D012697:Serine Endopeptidases; D000511:alpha-Macroglobulins / Q000494:pharmacology
D009363:Neoplasm Proteins; D000511:alpha-Macroglobulins; D002403:Cathepsins; D012697:Serine Endopeptidases; C534094:CTSG protein, human; D056649:Cathepsin G