Isolation of Two Permeability Globulins from Human Serum

Abstract

A PERMEABILITY factor, activated by dilution or surface contact, has been described in the β-globulin fraction of human serum¹. This substance, designated PF/dil, seems to have much in common with the enzyme kalli-krein first noted by Frey². Whether the serum of any given species contains one, or more, permeability globulin has so far not been clear. Based on similarities of hypotensive and permeability properties, it has been suggested that PF/dil and serum kallikrein may be the same³. Indeed, di-isopropyl phosphofluoridate (DFP) and soybean trypsin inhibitor seem to inactivate both^4–6. Permeability globulins from guinea pig serum have been reported with the electrophoretic mobility of α₂ (ref. l) as well as γ-globulin⁷; whether this indicates two molecular species, or is an artefact of preparative procedures, is not certain. Early chromatographic work begun by one of us (J. P. L.) on certain lots of Cohn Fraction III, obtained commercially from human plasma, had suggested the presence of more than one non-dialysable permeability active substance. We wish to report the isolation of two permeability globulins, differing in their electrophoretic mobility and chromatographic behaviour, from sera of normal young men.