title: Human pancreatic chymotrypsinogen A: a non-competitive enzyme immunoassay, and molecular forms in serum and amniotic fluid.
abstract: A sandwich enzyme immunoassay has been developed for human pancreatic chymotrypsin(ogen) using polystyrene balls coated with specific IgG as the first antibody and peroxidase-labelled IgG as the second antibody. The detection limit was 0.5 microgram/l. A good parallelism was observed with the curves obtained from standard chymotrypsinogen A and chymotrypsin(ogen) present in pancreatic juice; however, a slight discrepancy in parallelism with chymotrypsin(ogen) present in serum and amniotic fluid was noticed. Chymotrypsinogen concentration in pancreatic juice was evaluated to represent 9% of total proteins. Mean values of chymotrypsin(ogen) in human sera were 24.6 +/- 8.3 micrograms/l in adults and 20.9 +/- 8.8 micrograms/l in newborns. In amniotic fluid at the 18th week of pregnancy the values were scattered (5-70 micrograms/l). The molecular forms of immunoreactive chymotrypsin(ogen) in normal serum and amniotic fluid have been investigated by gel filtration on Sephadex G-100. Two peaks of immunoreactive chymotrypsin(ogen) were observed in normal serum; the first peak elutes in a position consistent with a complex of chymotrypsin with serum inhibitor (Mr 76,000), and the second peak elutes with a molecular weight of approx. 25,000 corresponding to the elution position of free chymotrypsin(ogen). In normal amniotic fluid three peaks of immunoreactive material were present; the first and second peaks elute in the same position as in serum, and the third peak with a molecular weight of about 14,500 may represent a degraded form of chymotrypsin.
mesh_terms: D000328:Adult; D000653:Amniotic Fluid / Q000201:enzymology*; D002850:Chromatography, Gel; D002919:Chymotrypsinogen / Q000032:analysis* / Q000097:blood; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques / Q000592:standards; D007231:Infant, Newborn; D008970:Molecular Weight; D010189:Pancreatic Juice / Q000201:enzymology*; D011247:Pregnancy; D014357:Trypsin / Q000032:analysis / Q000097:blood
chemical_list: D002919:Chymotrypsinogen; D014357:Trypsin