Proteinase inhibitor II from potatoes: isolation and characterization of its protomer components

Biochemistry ◽  
1976 ◽  
Vol 15 (16) ◽  
pp. 3418-3424 ◽  
Author(s):  
Joel Bryant ◽  
Terrence R. Green ◽  
T. Gurusaddaiah ◽  
Clarence A. Ryan
Keyword(s):  
Proteinase Inhibitor ◽  
Isolation And Characterization ◽  
Proteinase Inhibitor Ii

scholarly journals Proteinase inhibitors in rat serum. Purification and partial characterization of three functionally distinct trypsin inhibitors

1984 ◽  
Vol 218 (3) ◽  
pp. 953-959 ◽  
Author(s):  
L Kuehn ◽  
M Rutschmann ◽  
B Dahlmann ◽  
H Reinauer
Keyword(s):  
Proteinase Inhibitor ◽  
Proteinase Inhibitors ◽  
Serine Proteinase ◽  
The Other ◽  
Serine Proteinases ◽  
Rat Serum ◽  
Apparent Homogeneity ◽  
Human Counterpart ◽  
Proteinase Inhibitor Ii

Three different serine proteinase inhibitors were isolated from rat serum and purified to apparent homogeneity. One of the inhibitors appears to be homologous to alpha 1-proteinase inhibitor isolated from man and other species, but the other two, designated rat proteinase inhibitor I and rat proteinase inhibitor II, seem to have no human counterpart. alpha 1-Proteinase inhibitor (Mr 55000) inhibits trypsin, chymotrypsin and elastase, the three serine proteinases tested. Rat proteinase inhibitor I (Mr 66000) is active towards trypsin and chymotrypsin, but is inactive towards elastase. Rat proteinase inhibitor II (Mr 65000) is an effective inhibitor of trypsin only. Their contributions to the trypsin-inhibitory capacity of rat serum are about 68, 14 and 18% for alpha 1-proteinase inhibitor, rat proteinase inhibitor I and rat proteinase inhibitor II respectively.

scholarly journals Isolation and characterization of human plasma α 1-proteinase inhibitor and a conformational study of its interaction with proteinases

1976 ◽  
Vol 157 (2) ◽  
pp. 339-351 ◽  
Author(s):  
J Saklatvala ◽  
G C Wood ◽  
D D White
Keyword(s):  
Human Plasma ◽  
Isoelectric Focusing ◽  
Proteinase Inhibitor ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Sedimentation Equilibrium ◽  
Isolation And Characterization ◽  
Step Procedure ◽  
Helical Content

1. alpha 1-Proteinase inhibitor was isolated from human plasma by a five-step procedure. Isoelectric focusing showed that six components focused between pH4.85 and 4.95. 2. The mol.wt. of the inhibitor was 52000 by sedimentation equilibrium and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. The amino acid and carbohydrate compositions of the inhibitor were also determined. 3. The far-u.v.c.d. (circular-dichroism) spectrum indicated that the inhibitor had about 36% alpha-helical content. 4. The loss of proteinase-inhibitory activity when the inhibitor was exposed to pH values less than 5.0 or greater than 10.5 was accompanied by small changes in the far-u.v.c.d. spectrum and large changes in the near-u.v.c.d. spectrum. The change at alkaline pH was associated with ionization of tyrosine residues. 5. Interaction of inhibitor with chymotrypsin caused perturbation of the c.d. spectrum and this was used to follow the interaction and show a 1:1 stoicheiometry. 6. C.d., electrophoresis and isoelectric focusing showed that the inhibitor-enzyme complex is degraded by free enzyme. 7. Parallel studies with trypsin indicated that it too forms a 1:1 complex with inhibitor and is degraded by excess of enzyme.

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