Characterization of the metabolites of methyl n-butyl ketone, methyl iso-butyl ketone, and methyl ethyl ketone in guinea pig serum and their clearance

1. Methods for the separation from guinea pig serum in highly purified form of three of the components of complement are described. These substances are the so called mid-piece, end-piece, and 4th component. 2. Mid-piece has been separated as a euglobulin, with an electrophoretic mobility of 2.9 x 10–5 in phosphate buffer of ionic strength 0.2 at pH 7.7, and with a sedimentation constant of 6.4 x 10–13 in potassium chloride of ionic strength 0.2. 3. End-piece and 4th component were found together in a euglobulin fraction of serum which contained 10.3 per cent carbohydrate and had an electrophoretic mobility of 4.2 x 10–5 in phosphate buffer of ionic strength 0.2 at pH 7.7.

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191. Primary photochemical reactions. Part IV. Decomposition of methyl ethyl ketone and methyl butyl ketone

Journal of the Chemical Society (Resumed) ◽

10.1039/jr9340000874 ◽

1934 ◽

pp. 874 ◽

Cited By ~ 35

Author(s):

Ronald G. W. Norrish ◽

Margaret E. S. Appleyard

Keyword(s):

Methyl Ethyl Ketone ◽

Photochemical Reactions ◽

Methyl Ethyl ◽

Butyl Ketone

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Characterization of VOx-TiO2 catalysts and their activity in the partial oxidation of methyl ethyl ketone

Journal of Molecular Catalysis A Chemical ◽

10.1016/j.molcata.2007.11.001 ◽

2008 ◽

Vol 280 (1-2) ◽

pp. 122-130 ◽

Cited By ~ 22

Author(s):

Thomas Machold ◽

Wladimir Y. Suprun ◽

Helmut Papp

Keyword(s):

Methyl Ethyl Ketone ◽

Partial Oxidation ◽

Methyl Ethyl

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The identification and characterization of two separate carboxylesterases in guinea-pig serum

Biochemical Journal ◽

10.1042/bj2150091 ◽

1983 ◽

Vol 215 (1) ◽

pp. 91-99 ◽

Cited By ~ 12

Author(s):

K Cain ◽

E Reiner ◽

D G Williams

Keyword(s):

Guinea Pig ◽

Sodium Dodecyl Sulphate ◽

Enzyme Preparation ◽

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Selective Inhibitor ◽

Nitrophenyl Phosphate ◽

Phosphate Treatment ◽

Pig Serum

The esterase activity of guinea-pig serum was investigated. A 3-fold purification was achieved by removing the serum albumin by Blue Sepharose CL-6B affinity chromatography. The partially purified enzyme preparation had carboxylesterase and cholinesterase activities of 1.0 and 0.22 mumol of substrate/min per mg of protein respectively. The esterases were labelled with [3H]di-isopropyl phosphorofluoridate (DiPF) and separated electrophoretically on sodium dodecyl sulphate/polyacrylamide gels. Two main labelled bands were detected: band I had Mr 80 000 and bound 18-19 pmol of [3H]DiPF/mg of protein, and band II had Mr 58 000 and bound 7 pmol of [3H]DiPF/mg of protein. Bis-p-nitrophenyl phosphate (a selective inhibitor of carboxylesterase) inhibited most of the labelling of bands I and II. The residual labelling (8%) of band I but not band II (4%) was removed by preincubation of partially purified enzyme preparation with neostigmine (a selective inhibitor of cholinesterase). Paraoxon totally prevented the [3H]DiPF labelling of the partially purified enzyme preparation. Isoelectrofocusing of [3H]DiPF-labelled and uninhibited partially purified enzyme preparation revealed that there were at least two separate carboxylesterases, which had pI3.9 and pI6.2, a cholinesterase enzyme (pI4.3) and an unidentified protein that reacts with [3H]DiPF and has a pI5.0. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis of these enzymes showed that the carboxylesterase enzymes at pI3.9 and pI6.2 corresponded to the 80 000-Mr subunit (band I) and 58 000-Mr subunit (band II). The cholinesterase enzyme was also composed of 80 000-Mr subunits (i.e. the residual labelling in band I after bis-p-nitrophenyl phosphate treatment). The unidentified protein at pI5.0 corresponded to the residual labelling in band II (Mr 58 000), which was insensitive to neostigmine and bis-p-nitrophenyl phosphate. These studies show that the carboxylesterase activity of guinea-pig serum is the result of at least two separate and distinct enzymes.

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