Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.5.1.4 (deaminase)
 5,113 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human bone marrow cultured in the presence of human rIL-3 has been reported to give rise to basophils. In contrast, mouse bone marrow, cultured in the presence of mouse IL-3, leads to the growth of mast cells. To determine if human rIL-3 might also stimulate the growth of human mast cells, we cultured human bone marrow in the presence of human rIL-3 in suspension cultures, methylcellulose, and in "interphase" cultures where cells are layered over agar. The presence of mast cells was determined using a variety of histochemical techniques. In agreement with previous reports, basophil-like cells were identified in all culture systems. Mastlike cells were identified only in interphase cultures. By 3 wk, such cultures consisted of basophil-like cells (20 to 50%) and mastlike cells (1 to 5%). Cultures supplemented with rIL-4 showed no additional increase in basophil-like and mastlike cells. Both basophil-like and mastlike cells fluoresced with o-phthaldialdehyde and exhibited IgE receptors. Unlike basophil-like cells, mastlike cells were chloroacetate esterase, amidase, and human mast cell tryptase positive. We conclude that human rIL-3 can support the growth of human mastlike cells under selected culture conditions.
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PMID:IL-3-dependent growth of basophil-like cells and mastlike cells from human bone marrow. 264 50

Conversion of the biophysically active large surfactant aggregate subtype (LA) of alveolar surfactant into the less surface active small surfactant aggregates (SA) occurs in vivo and is reproduced under conditions of cyclic surface area changes in vitro. A serine-active carboxyl esterase has been suggested as the responsible enzymatic activity, although the exact mechanisms underlying the conversion process are presently unclear. We investigated the influence of exogenous serine proteases and synthetic and natural serine protease inhibitors on the conversion kinetics of natural rabbit surfactant, obtained as bronchoalveolar lavage fluid (BALF). In vitro cycling of BALF was performed for various time periods in the absence or presence of increasing amounts of several serine proteases (trypsin, plasmin, thrombin, tryptase), and one natural (aprotinin) and 25 synthetic serine protease inhibitors (including regular benzamidines [group A], 3-amidinophenylalanine derivatives [group B], bis-benzamidines [group C], and analogs of naphthylsulfonyl-glycyl-4-amidinophenylalanine piperidide [group D]). LA were separated from SA by 48,000 x g centrifugation. Surface activity of the LA fraction was measured by means of the pulsating bubble surfactometer. None of the "classical" serine proteases forwarded any acceleration of the LA-to-SA conversion kinetics. Some of the serine protease inhibitors caused moderate retardation of conversion, but at the same dose range inhibited the surface tension-lowering properties of the LA fraction, which per se explained their inhibitory effect. In contrast, specific dose-dependent inhibition of the LA-to-SA transition was observed for four derivatives of the bis-benzamidine group: full blockage of conversion over 240 min of cycling was noted at doses that did not interfere with the surface activity of the LA fraction. In addition, the prototype of these bis-benzamidines, 1,4-bis-[beta-naphthylsulfonyl-(3-aminophenylalanine)]-piperazide, was found to inhibit the activity of the rabbit liver carboxylesterase ES-2 in two different synthetic substrate assays reflecting the amidase and esterase properties of carboxylesterases. These findings support the hypothesis that the LA-to-SA conversion is an enzymatically-driven process with serine-active carboxyl esterase(s) being centrally involved. Synthetic bis-benzamidine-type serine protease inhibitors may offer specific inhibition of this event.
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PMID:Selective inhibition of large-to-small surfactant aggregate conversion by serine protease inhibitors of the bis-benzamidine type. 1249 37