Kallikrein modification with affinity to IgG present in higher amounts than normal in plasma from patients with Crohn's disease.

This study presents immunological and functional evidence to suggest that the activation of prekallikrein (PK) in human plasma yields two modifications of kallikrein. One of these modifications showed amidolytic properties strongly deviating from those registered for the main part of the enzyme. The substrates were S-2302, Bz-Pro-Phe-Arg-pNA, S-2366 and S-2222.

Part of purified human plasma kallikrein removed together with a remaining IgG fraction--immunoblot experiments and functional tests.

In the present study it is shown that a preparation of highly purified plasma kallikrein (specific activity 81 S-2302 U/mg) still contained small amounts of an IgG fraction. Amidase assays of the fresh enzyme with four peptide substrates (S-2302, Bz-Pro-Phe-Arg-pNA, S-2366, S-2222) did not reveal any inhomogeneity, and immunoblot experiments with antibodies against prekallikrein yielded only an 85 kD double band. After a storage period (2 years at -70 degrees C), S-2366 and S-2222 amidase activities not reflecting the initial kallikrein appeared.

Removal of IgG from normal plasma and plasma from untreated patients with active Crohn's disease--effect on levels of contact factors.

Protein G columns were used to remove IgG from human plasma, and the effect on levels of factor XII, factor XI and prekallikrein was studied in functional tests. IgG was detected in PAGE immunoblot experiments with Fc-specific antibodies. Removal of the bulk of IgG in a procedure based on a low plasma dilution (1+2.

Part of prekallikrein removed from human plasma together with IgG--immunoblot experiments and functional tests.

With the present study, evidence is provided that prekallikrein (PK) in human plasma might be present in two different states, one of them removed along with IgG on Protein G columns. At a plasma dilution of 1 + 2.5, small amounts of an IgG fraction were left in plasma along with all of the PK.

Contact activation factors in plasma from women on estrogen replacement therapy after ovariohysterectomy.

The plasma levels of factor XII, prekallikrein, factor XI, and high molecular weight kininogen were studied in women with bilateral oophorectomy and hysterectomy who received hormone replacement therapy with a 2 mg daily dose of estradiol valerate. Also plasminogen activator activity was investigated. The observations made provide support for the assumption that the low doses of estrogen used in hormone replacement therapy do not significantly affect the levels of contact activation or fibrinolytic factors in plasma.