scholarly journals The separation and characterization of the methylumbelliferyl β-galactosidases of human liver

1976 ◽  
Vol 157 (1) ◽  
pp. 189-195 ◽  
Author(s):  
P S Cheetham ◽  
N E Dance

1. A previously uncharacterized form of human liver acid beta-galactosidase (EC 3.2.1.23), possibly a dimer of molecular weight 160 000, was resolved by gel filtration. It has the same ability to hydrolyse GM1 ganglioside as the two other acid beta-galactosidase forms. 2. The low-molecular-weight forms of acid beta-galactosidase undergo salt-dependent aggregation. 3. The high-molecular-weight component may consist of the low-molecular-weight forms bound to membrane fragments. It can be converted completely into a mixture of these forms. 4. The neutral beta-galactosidase activity can be resolved into two forms by DEAE-cellulose chromatography. They differ in their response to Cl-ions. 5. A new nomenclature is suggested for the six beta-galactosidases so far found in human liver. 6. The enzymic constituents of the beta-galactosidase bands resolved by electrophoresis were re-examined. The A band contains three components. A two-dimensional electrophoretic procedure for resolving the A band is described. 7. The effect of neuraminidase treatment on the behaviour of beta-galactosidases in various separation systems is examined.

1978 ◽  
Vol 173 (1) ◽  
pp. 191-196 ◽  
Author(s):  
M Carroll

Those proteins of human liver that cross-reacted with antibodies raised to apparently homogenous hexosamindases A and B were detected by immunodiffusion. Cross-reacting proteins with high molecular weights (greater than 2000000) and intermediate molecular weights (70000–200000) were present both in the unadsorbed fraction and in the 0.05–0.2M-NaCl eluate obtained by DEAE-cellulose chromatography at pH7.0. The unadsorbed fraction also contained a cross-reacting protein of low molecular weight (10000–70000). The possible structural and functional relationships between hexosaminidase and the cross-reacting proteins are discussed. An apparently cross-reacting protein present in the 0.05M-NaCl eluate from the DEAE-cellulose column was serologically unrelated to hexosaminidase, but it gave a reaction of immunological identify with one of the apparently cross-reacting proteins having the charge and size characteristics of hexosaminidase A. It is suggested that immunochemical methods may provide criteria for the homogeneity of enzyme preparations superior to those of conventional methods.


1984 ◽  
Vol 62 (5) ◽  
pp. 276-279 ◽  
Author(s):  
C. H. Lin ◽  
W. Chung ◽  
K. P. Strickland ◽  
A. J. Hudson

An isozyme of S-adenosylmethionine synthetase has been purified to homogeneity by ammonium sulfate fractionation, DEAE-cellulose column chromatography, and gel filtration on a Sephadex G-200 column. The purified enzyme is very unstable and has a molecular weight of 120 000 consisting of two identical subunits. Amino acid analysis on the purified enzyme showed glycine, glutamate, and aspartate to be the most abundant and the aromatic amino acids to be the least abundant. It possesses tripolyphosphatase activity which can be stimulated five to six times by S-adenosylmethionine (20–40 μM). The findings support the conclusion that an enzyme-bound tripolyphosphate is an obligatory intermediate in the enzymatic synthesis of S-adenosylmethionine from ATP and methionine.


1971 ◽  
Vol 124 (2) ◽  
pp. 337-343 ◽  
Author(s):  
Abraham Spector ◽  
Lu-Ku Li ◽  
Robert C. Augusteyn ◽  
Arthur Schneider ◽  
Thomas Freund

α-Crystallin was isolated from calf lens periphery by chromatography on DEAE-cellulose and gel filtration. Three distinct populations of macromolecules have been isolated with molecular weights in the ranges approx. 6×105−9×105, 0.9×106−4×106and greater than 10×106. The concentration of macromolecules at the molecular-weight limits of a population are very low. The members of the different populations do not appear to be in equilibrium with each other. Further, in those molecular-weight fractions investigated, no equilibrium between members of the same population was observed. The population of lowest molecular weight comprises 65–75% of the total material. The amino acid and subunit composition of the different-sized fractions appear very similar, if not identical. The only chemical difference observed between the fractions is the presence of significant amounts of sugar in the higher-molecular-weight fractions. Subunit molecular weights of approx. 19.5×103and 22.5×103were observed for all α-crystallin fractions.


1970 ◽  
Vol 1 (2) ◽  
pp. 164-168
Author(s):  
Thomas M. Daniel ◽  
Lavenia E. Ferguson

Two proteins have been purified from culture filtrates of Mycobacterium tuberculosis , H 37 Ra strain by a procedure combining gel filtration, diethylaminoethyl (DEAE)-cellulose chromatography, and zone electrophoresis. The two proteins are similar in molecular weight but differ slightly in charge. The faster migrating protein, designated a 1 , is not antigenic. The slower migrating protein, designated a 2 , is antigenic both with respect to antisera and as a skin-testing antigen.


1979 ◽  
Vol 178 (2) ◽  
pp. 279-287 ◽  
Author(s):  
D K Podolsky ◽  
M M Weiser

A low-molecular-weight acceptor of galactosyltransferase activity was detected in sera and effusions of patients with extensive maligant disease. This substance was purified to homogeneity from both human serum and effusion by using sequential charcoal/Celite and DEAE-cellulose column chromatography. The purified acceptor was shown to act as substrate for both purified normal and cancer-associated human galactosyltransferase (EC 2.4.1.22) isoenzymes, but had a higher affinity for the cancer-associated isoenzyme (Km = 20 microM) than for the normal isoenzyme (Km = 500 microM). The substrate was found to be a glycopeptide with mol.wt. approx. 3600 determined by polyacrylamide-gel chromatography. Carbohyydate analysis demonstrated only the presence of glucosamine and mannose. Amino acid analysis revealed that the peptide moiety consisted of eight different amino acids, including two residues of asparagine and one residue of serine, but no threonine. These structural data suggest that the acceptor is a fraction of an asparagine-glucosamine type of glycoprotein.


1984 ◽  
Vol 62 (6) ◽  
pp. 449-455 ◽  
Author(s):  
Show-Jy Lau ◽  
Bibudhendra Sarkar

The binding of six trace metals, Mn(II), Ni(II), Zn(II), Cu(II), Cd(II) and Fe(III), to human cord serum has been studied by Sephadex G-100 gel filtration at physiological pH, using radioisotopes as tracers. The results are compared with those obtained from adult serum. In both cord and adult sera, extensive amounts of the metals are bound to high molecular weight proteins. Among them, Fe(III) is mostly bound to transferrin; Ni(II), Zn(II), Cu(II), and Cd(II) are bound to albumin and other macro-molecules. The binding of Mn(II) either to transferrin or albumin is not resolved. Small fractions of Zn(II), Cu(II), and Cd(II) and large fractions of Mn(II) and Ni(II) are found to be associated with low molecular weight components of both sera. The distribution varies from metal to metal. However, the low molecular weight component of the size 1500 – 10 000 is present in all the metals studied. Further purification of this component was attempted by DEAE-cellulose ion-exchange chromatography. The possible identity as well as the biological role played by this particular component of serum in the transport of metals in blood and across membranes is discussed.


1986 ◽  
Vol 234 (1) ◽  
pp. 157-162 ◽  
Author(s):  
N N Dewji ◽  
D R De-Keyzer ◽  
J L Stirling

beta-N-Acetylhexosaminidase I2 was purified from human liver by a combination of concanavalin A chromatography, DEAE-cellulose chromatography, gel filtration and affinity chromatography on 2-acetamido-N-(6-aminohexanoyl)-2-deoxy-beta-D-glucopyranosylamine coupled to CNBr-activated Sepharose 4B. Its specific activity was 130 mumol/min per mg of protein compared with values of 150 and 320 mumol/min/mg of protein for beta-N-acetylhexosaminidases A and B purified from the same tissue. Km values for I2, A and B were 1.0 mM, 0.8 mM and 0.74 mM respectively. On gradient gel electrophoresis under non-denaturing conditions, hexosaminidase I2 behaved similarly to A and appeared to have an Mr between 100 000 and 110 000. beta-N-Acetylhexosaminidase I2 was resolved into two major polypeptides, of Mr 56 000 and 29 000, on SDS/polyacrylamide-gel electrophoresis under denaturing conditions. Immunoblotting with anti-(hexosaminidase alpha-subunit) serum confirmed that the 56 000-Mr component was the alpha-subunit and anti-(hexosaminidase B) serum reacted with the 29 000 Mr component. beta-N-Acetylhexosaminidase I2 more closely resembles form A than B, but the features of its structure that allow it to be separated from A on the basis of net charge have not yet been found.


1983 ◽  
Vol 61 (1) ◽  
pp. 54-62 ◽  
Author(s):  
Kiyoshi Takeuchi

Exo-β-1,3-glucanase from the sea urchin embryos was purified 114-fold from the initial hatching supernatant by the following procedures: (a) gel filtration on Sephadex G-100; (b) hydrophobic chromatography on 4-phenylbutylamine-Sepharose (PBA-Sepharose); (c) two ion-exchange chromatographic steps on DEAE-cellulose; (d) gel filtration on Ultrogel AcA 34; (e) gel filtration on Sephadex G-100. The purified enzyme contained 2.2% carbohydrate and gave a single protein band corresponding to a molecular weight of 136 000 following electrophoresis on sodium dodecyl sulfate (SDS) – urea – polyacrylamide gel. Gel filtration on Ultrogel AcA 34 with a nondenaturing solvent gave a molecular weight of 130 000 ± 6000. The enzyme displayed an optimum pH at 5.0–5.5 and hydrolysed laminarin and PS(curdlan)-beads at the nonreducing ends, releasing glucose. Although activity of the purified enzyme was not affected by SDS, urea, some divalent ions, and 2-mercaptoethanol, both dithiothreitol and Hg2+ were markedly inhibitory.


Blood ◽  
1969 ◽  
Vol 33 (6) ◽  
pp. 899-908 ◽  
Author(s):  
CHRISTINE LAWRENCE

Abstract The binding of vitamin B12 by serum proteins was studied by separating Co57B12-enriched serum by Sephadex gel filtration, column chromatography with DEAE-cellulose, and paper electrophoresis. Each method of separation yielded two discrete B12-binding fractions. However, the analysis of each serum by all three separation technics indicated that one of the fractions was, in each case, bipartite. The "high" molecular weight B12-binding fraction defined by Sephadex gel filtration consisted of transcobalamin I and just part of the transcobalamin II fraction. The remaining portion of transcobalamin II was eluted from Sephadex gel in a "low" molecular weight fraction. Thus, transcobalamin II, equivalent to the β-globulin B12-binder, consisted of both "high" and "low" molecular weight components. This suggests that there are at least three serum proteins that can bind vitamin B12: two β-globulins, together comprising the transcobalamin II fraction and differing in molecular weight; and transcobalamin I.


1999 ◽  
Vol 30 (2) ◽  
pp. 114-119 ◽  
Author(s):  
Claudio Henrique Cerri e Silva ◽  
Jurgen Puls ◽  
Marcelo Valle de Sousa ◽  
Edivaldo Ximenes Ferreira Filho

A xylan-degrading enzyme (xylanase II) was purified to apparent homogeneity from solid-state cultures of Aspergillus fumigatus Fresenius. The molecular weight of xylanase II was found to be 19 and 8.5 kDa, as estimated by SDS-PAGE and gel filtration on FPLC, respectively. The purified enzyme was most active at 55 °C and pH 5.5. It was specific to xylan. The apparent Km and Vmax values on soluble and insoluble xylans from oat spelt and birchwood showed that xylanase II was most active on soluble birchwood xylan. Studies on hydrolysis products of various xylans and xylooligomers by xylanase II on HPLC showed that the enzyme released a range of products from xylobiose to xylohexaose, with a small amount of xylose from xylooligomers, and presented transferase activity.


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