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Human Leukocyte Migration Inhibitory Factor (LIF)
Author(s) -
BENDTZEN K.
Publication year - 1977
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1111/j.1365-3083.1977.tb00327.x
Subject(s) - pmsf , phenylmethylsulfonyl fluoride , serine protease , chemistry , serine , protease , aprotinin , biochemistry , concanavalin a , enzyme , esterase , sodium fluoride , tosyl , enzyme inhibitor , fluoride , in vitro , stereochemistry , medicine , inorganic chemistry
The activity of leukocyte migration inhibitory factor (LIF) obtained from Sephadex‐G‐100‐chromatographed supernatants of concanavalin‐A‐stimulated human lymphocytes was suppressed by two synthetic serine esterase and serine protease inhibitors (di‐isopropylfluorophosphate (DFP) and phenylmethylsulfonyl fluoride (PMSF)). LIF activity was also reduced by the naturally occurring protease inhibitors soybean trypsin inhibitor and aprotinin. The observed effect of DFP and PMSF was irreversible, since elimination of the inhibitors by dialysis did not restore LIF activity. The effect of PMSF was dose‐, time‐, and temperature‐dependent, and hydrolytic products of PMSF as well as sodium fluoride were inactive in blocking LIF. These results suggest that LIF may act as a serine esterase or a serine protease, or both of these, and that this putative enzyme is present in an activated form in supernatants from mitogen‐stimulated mononuclear cells.