MULTIPLE FORMS OF HUMAN LIVER ESTERASES

1965 ◽  
Vol 43 (5) ◽  
pp. 595-602 ◽  
Author(s):  
D. J. Ecobichon

Zone electrophoresis in starch gel of the water-soluble human liver esterases resulted in the separation of three zones of activity, each composed of several bands. The relative sizes of the enzymes in each zone were studied by utilizing the relative retardation of the electrophoretic migration induced by changes in the concentration of starch. On the basis of graphic analysis, four esterase bands comprising the zone migrating towards the cathode were found to be similar in molecular size or shape. A similar observation was made for seven bands comprising a zone migrating towards the anode. Taken with the substrate specificities and sensitivities toward various inhibitors, these observations strengthen the hypothesis that at least two of the hepatic esterases, an acetylesterase and an aliesterase, exist as multiple forms, differing primarily in net electrical charge.

1961 ◽  
Vol 39 (9) ◽  
pp. 1329-1332 ◽  
Author(s):  
D. J. Ecobichon ◽  
W. Kalow

Zone electrophoresis on starch gel in conjunction with various histochemical staining methods was applied to the study of the water-soluble esterases of liver. The results indicated that in regard to electrophoretic migration and enzymatic properties, none of the human liver esterases was identical with any of the human serum esterases.


1966 ◽  
Vol 44 (2) ◽  
pp. 225-232 ◽  
Author(s):  
D. J. Ecobichon

Water-soluble proteins and enzymes of human brain were separated by vertical zone electrophoresis in starch gel. Fifteen bands of esterase activity were detected in brain. Various substrates and inhibitors were used in efforts to identify enzymes in addition to a comparison of the esterase pattern with patterns obtained from other human tissues. One zone, composed of four bands of acetylesterase activity, was found to be common to all the tissues investigated with the exception of serum. Two bands of cholinesterase and two bands of A-esterase activity were identified. The remaining bands, which were aliesterases possessing broad overlapping substrate specificity and inhibitor sensitivity, were electrophoretically different from those of other tissues. Observations on alkaline phosphatase, acid phosphatase, and lactate dehydrogenase were recorded for comparison with the data on esterases.


1965 ◽  
Vol 43 (1) ◽  
pp. 73-79 ◽  
Author(s):  
D. J. Ecobichon ◽  
W. Kalow

Water-soluble proteins and enzymes of human skeletal and smooth muscle were separated by vertical-zone electrophoresis in starch gel and compared with those of human liver and kidney. Thirteen bands of proteins were detected with amido black in skeletal muscle, five of which were also detected in smooth muscle. Various substrates and inhibitors were used in efforts to identify enzymes. Ten bands of esterase activity were detected in skeletal muscle, and nine in smooth muscle. One zone, characteristic of serum cholinesterase, was believed to be due to serum contained in the tissue. A zone of isozymic esterases found in skeletal and smooth muscle was similar to a zone in human liver and kidney and reacted like an acetylesterase. Other esterase bands, which showed a marked hydrolysis of α-naphthyl butyrate, were similar to aliesterases of renal tissue. Observations on alkaline phosphatase, acid phosphatase, aminopeptidase, lactate dehydrogenase, and catalase were recorded for comparison with the data on esterases.


1967 ◽  
Vol 45 (7) ◽  
pp. 1099-1105 ◽  
Author(s):  
D. J. Ecobichon ◽  
Y. Israel

The water-soluble esterases of a microsome-free supernatant of the electric tissue of Electrophorus electricus were separated by vertical-zone electrophoresis in starch gel. Specific and nonspecific substrates and inhibitors were used in conjunction with histochemical techniques to identify the enzymes. Acetylcholinesterase was present in the form of four bands of activity, the electrophoretic mobility of which was suggestive of aggregated forms of the enzyme. Pseudocholinesterase was detected as two weak bands of activity. A third esterase was identified as a nonspecific carboxylesterase and shown to be a sialoprotein.


1965 ◽  
Vol 43 (11) ◽  
pp. 1779-1786 ◽  
Author(s):  
H. F. MacRae ◽  
C. J. Randall

Water-soluble esterases of certain bovine skeletal muscles were separated by horizontal zone electrophoresis in starch gel in a discontinuous ouffer system. Eighteen bands of esterase activity were detected by the use of α-naphthyl acetate and α-naphthyl butyrate as substrates. Other substrates and various inhibitors were used to characterize the separated enzymes. A group of presumed isozymic esterases (three bands), which hydrolyzed α-naphthyl butyrate but not any other substrate tested, was sensitive to organophosphates, was heat labile, and was classified as aliesterase or, more specifically, as butyrylesterase. Another group of presumed isozymic esterases (four bands) hydrolyzed only α-naphthyl acetate and indoxyl acetates, was heat stable and resistant to organophosphates, and was tentatively classified as arylesterase or cathepsin. Eleven heat-labile esterase bands hydrolyzed both α-naphthyl acetate and α-naphthyl butyrate, were sensitive to organophosphates, and were classified as nonspecific aliesterases.


1974 ◽  
Vol 137 (1) ◽  
pp. 123-125 ◽  
Author(s):  
S. R. Levinson ◽  
J. C. Ellory

The molecular size of acetylcholinesterase (EC 3.1.1.7) from the electric organ of Electrophorus electricus and erythrocyte ‘ghosts’ was estimated in both membrane-bound and purified preparations by irradiation inactivation. Results suggest that the form of the enzyme in the membrane is a monomer of molecular weight approx. 75000 and that multiple forms of the enzyme observed in solubilized preparations are aggregates of this monomer.


1977 ◽  
Vol 17 (89) ◽  
pp. 1020 ◽  
Author(s):  
J McCausland ◽  
CW Wrigley

A range of laboratory methods was examined for their ability to distinguish between 19 barley cultivars currently grown in Australia. Aleurone colour, revealed after mechanical or chemical dehulling, differentiated Abyssinian, Atlas, Cape and Corvette from the other cultivars. Peroxidase and phenol testing were not useful. Seven different patterns were obtained for the hordeins of lowest mobility by starch gel electrophoresis. Further distinction was provided by flat gel isoelectric focusing of the water-soluble and hordein proteins for which 13 different pattern-groupings were obtained. The two electrophoretic techniques complemented one another, so that the use of both methods left only a few cultivars that could not be distinguished.


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