Determination of alpha 2-macroglobulin-trypsin complex with a new synthetic substrate.
We have developed a colorimetric assay for quantifying alpha 2-macroglobulin-trypsin complex (alpha 2M-TRY) in human serum, based on use of a new chromogenic substrate D-gamma-tert-butyloxy-Glu-Gly-Arg-3-carboxy-4-hydroxyanilide dihydrochloride (PS-3001). Within-run CVs by this assay were 4.76%, 1.57%, and 0.83% for trypsin complex concentrations of 3.1, 12.2, and 48.1 U/L, respectively (n = 10 each). Between-day CVs were 5.38%, 3.12%, and 2.20% at each concentration, respectively (n = 7). Mean analytical recoveries of alpha 2M-TRY added to serum were 100%, 105%, and 101% for 9.2, 15.1, and 46.3 U/L, respectively (n = 2). The standard curve obtained was linear up to 330 U/L. We applied this method to the study of alpha 2M-TRY activity in sera from 97 healthy subjects (group 1), from 27 patients with acute pancreatitis (group 2), and from 25 patients with other chylopoietic diseases (group 3); results ranged from 0 to 1.2 U/L (mean = 0.5, SD = 0.3), from 1.2 to 77.4 U/L (mean = 14.6, SD = 19.0), and from 0 to 1.3 U/L (mean = 0.4, SD = 0.3), respectively. Concentrations of enzymatically active alpha 2M-TRY were significantly greater in sera from group 2 than in groups 1 and 3. The determination of serum alpha 2M-TRY activity by this simple, rapid, colorimetric method may be useful for the diagnosis and evaluation of pancreatic disease.
Kuroiwa
K
K
Nitto Boseki Co., Ltd., Biochemical Laboratory, Fukushima-Pref., Japan.
Nakatsuyama
S
S
Katayama
K
K
Nagasawa
T
T
D000208:Acute Disease; D000813:Anilides / Q000378:metabolism*; D002863:Chromogenic Compounds; D003124:Colorimetry; D006801:Humans; D006868:Hydrolysis; D009842:Oligopeptides / Q000378:metabolism*; D010182:Pancreatic Diseases / Q000097:blood; D010195:Pancreatitis / Q000097:blood; D011786:Quality Control; D012016:Reference Values; D013379:Substrate Specificity; D014357:Trypsin / Q000032:analysis* / Q000378:metabolism; D000511:alpha-Macroglobulins / Q000032:analysis* / Q000378:metabolism
D000813:Anilides; D002863:Chromogenic Compounds; D009842:Oligopeptides; C028939:alpha-2-macroglobulin-trypsin complex; D000511:alpha-Macroglobulins; C061782:gamma-tert-butyloxy-Glu-Gly-Arg-3-carboxy-4-hydroxyanilide; D014357:Trypsin