title: Influence of inorganic phosphate on the activity determination of isoenzymes of alkaline phosphatase in various buffer systems.
abstract: The inhibitory effect of inorganic phosphate on the activity determination of isoenzymes of alkaline phosphatase (AP) in diethanolamine (DEA), glycine and 2-amino-2-methyl-1,3-propandiol (AMPD) buffer was studied. This effect depends on the buffer used and isoenzyme investigated. Especially the placental isoenzyme is inhibited; the inhibitory effect in DEA buffer is stronger than in the other buffers used. The requirement of purity for 4-nitrophenylphosphate with respect to its content of inorganic phosphate and conclusions for using control sera enriched with AP isoenzymes are discussed.
mesh_terms: D009597:4-Nitrophenylphosphatase / Q000032:analysis; D000469:Alkaline Phosphatase / Q000032:analysis* / Q000037:antagonists & inhibitors; D001842:Bone and Bones / Q000201:enzymology; D002021:Buffers; D004983:Ethanolamines / Q000592:standards; D005260:Female; D005998:Glycine / Q000592:standards; D006801:Humans; D007421:Intestine, Small / Q000201:enzymology; D007527:Isoenzymes / Q000032:analysis* / Q000037:antagonists & inhibitors; D008099:Liver / Q000201:enzymology; D009596:Nitrophenols / Q000592:standards; D009943:Organophosphorus Compounds / Q000592:standards; D010710:Phosphates / Q000494:pharmacology*; D010920:Placenta / Q000201:enzymology; D011247:Pregnancy; D011409:Propylene Glycols / Q000592:standards; D011786:Quality Control
chemical_list: D002021:Buffers; D004983:Ethanolamines; D007527:Isoenzymes; D009596:Nitrophenols; D009943:Organophosphorus Compounds; D010710:Phosphates; D011409:Propylene Glycols; C008644:nitrophenylphosphate; C020283:diethanolamine; C019250:2-amino-2-methyl-1,3-propandiol; D000469:Alkaline Phosphatase; D009597:4-Nitrophenylphosphatase; D005998:Glycine