High molecular weight soluble neutral maltase-glucoamylases in the intestine of the suckling rat

1990 ◽  
Vol 68 (9) ◽  
pp. 1103-1111 ◽  
Author(s):  
L. Lee ◽  
G. Forstner

Previous work from our laboratory has shown that the intestine of the suckling rat, unlike adult rat intestine, contains abundant quantities of at least two soluble neutral maltase-glucoamylases. These enzymes are related antigenically to membrane-bound maltase-glucoamylase, which predominates in adult intestine, but are either more easily solubilized or occupy a different cellular locus. To study the soluble enzymes further, we attempted their isolation from the intestine of 11-day-old suckling rats. Initial attempts were complicated by proteolytic degradation, despite the addition of phenylmethylsulfonyl fluoride, N-ethylmaleimide, leupeptin, pepstatin, and EDTA to buffers used for homogenization and column chromatography. Addition of aprotinin, amastatin, bestatin, and phosphoramidone resulted, however, in the isolation of two stable, high molecular weight maltases (HM1 and HM2). Both enzymes eluted before a papain-solubilized membrane-derived maltase-glucoamylase on Sepharose 4B and were separable by DE-52 and Sepharose 6B – Tris affinity columns. They were further purified on a lentil lectin – Sepharose 4B column. Substrate specificities were almost the same and characteristic of maltase-glucoamylases. Hydrophobic binding properties and pH optima of HM1 and HM2 were also similar. HM1 was resolved by sodium dodecyl sulfate – polyacrylamide gel electrophoresis into approximately equal portions of an endo-β-N-acetylglucosaminidase H sensitive enzyme of molecular weight (MW) 200 000 and an endo-β-N-acetylglucosaminidase H resistant but endo-β-acetylglucosaminidase F sensitive enzyme of MW 400 000. In contrast, most of HM2 consisted of a doublet of MW 200 000 – 210 000 that was endo-β-N-acetylglucosaminidase H sensitive. The intestine of the suckling rat, therefore, contains two soluble maltase–glucoamylase fractions, with a major portion of high mannose rather than complex oligosaccharides. In HM1, it is possible that the high mannose derivative is transformed during trafficking into the complex endo-β-N-acetylglucosaminidase H resistant form. HM2 appears to undergo little oligosaccharide processing.Key words: soluble maltase-glucoamylases, suckling rats.

1980 ◽  
Vol 189 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Yoav Ben-Yoseph ◽  
Melinda Hungerford ◽  
Henry L. Nadler

Galactocerebrosidase (β-d-galactosyl-N-acylsphingosine galactohydrolase; EC 3.2.1.46) activity of brain and liver preparations from normal individuals and patients with Krabbe disease (globoid-cell leukodystrophy) have been separated by gel filtration into four different molecular-weight forms. The apparent mol.wts. were 760000±34000 and 121000±10000 for the high- and low-molecular-weight forms (peaks I and IV respectively) and 499000±22000 (mean±s.d.) and 256000±12000 for the intermediate forms (peaks II and III respectively). On examination by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, the high- and low-molecular-weight forms revealed a single protein band with a similar mobility corresponding to a mol.wt. of about 125000. Antigenic identity was demonstrated between the various molecular-weight forms of the normal and the mutant galactocerebrosidases by using antisera against either the high- or the low-molecular-weight enzymes. The high-molecular-weight form of galactocerebrosidase was found to possess higher specific activity toward natural substrates when compared with the low-molecular-weight form. It is suggested that the high-molecular-weight enzyme is the active form in vivo and an aggregation process that proceeds from a monomer (mol.wt. approx. 125000) to a dimer (mol.wt. approx. 250000) and from the dimer to either a tetramer (mol.wt. approx. 500000) or a hexamer (mol.wt. approx. 750000) takes place in normal as well as in Krabbe-disease tissues.


Blood ◽  
1988 ◽  
Vol 71 (5) ◽  
pp. 1268-1276 ◽  
Author(s):  
F van Iwaarden ◽  
PG de Groot ◽  
JJ Sixma ◽  
M Berrettini ◽  
BN Bouma

Abstract The presence of high-molecular weight (mol wt) kininogen was demonstrated in cultured human endothelial cells derived from the umbilical cord by immunofluorescence techniques. Cultured human endothelial cells contain 58 +/- 11 ng (n = 16) high-mol wt kininogen/10(6) cells as determined by an enzyme-linked immunosorbent assay (ELISA) specific for high-mol wt kininogen. High-mol wt kininogen was isolated from cultured human endothelial cells by immunoaffinity chromatography. Nonreduced sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that endothelial cell high-mol wt kininogen consisted of five protein bands with mol wts of 95,000, 85,000, 65,000, 46,000, and 30,000 daltons. Immunoblotting of the endothelial cell high-mol wt kininogen by using specific antisera against the heavy and light chain indicated that the 95,000-, 85,000-, and 65,000-dalton bands consisted of the heavy and light chain whereas the 46,000- and 30,000-dalton bands reacted only with the anti-light chain antiserum. Immunoprecipitation studies performed with lysed, metabolically labeled endothelial cells and monospecific antisera directed against high-mol wt kininogen suggested that high-mol wt kininogen is not synthesized by the endothelial cells. Endothelial cells cultured in high-mol wt kininogen-free medium did not contain high-mol wt kininogen. These studies indicate that endothelial cell high-mol wt kininogen was proteolytically cleaved in the culture medium and subsequently internalized by the endothelial cells. Binding and internalization studies performed with 125I-labeled, proteolytically cleaved, high-mol wt kininogen showed that endothelial cells can indeed bind and internalize proteolytically cleaved high-mol wt kininogen in a specific and saturable way.


1984 ◽  
Vol 44 (2) ◽  
pp. 117-123 ◽  
Author(s):  
N. K. Singh ◽  
K. W. Shepherd

SUMMARYThe gene(s) controlling the high-molecular-weight glutelin subunits in rye (designated as Glu-Rl) was mapped with respect to the centromere using a 1RL-1DS wheat-rye translocation line and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Analysis of 479 seeds from test-crosses between a 1R/1RL-1DS heterozygote and the cultivar India 115, revealed 14·6% aneuploid and 3·95% recombinant progeny. Excluding the aneuploids, this locus was calculated to be 4·65 ± 1·04 cM from the centromere on the long arm of chromosome 1R, which is comparable to the position of the homoeologous loci in wheat and barley.


2000 ◽  
Vol 51 (3) ◽  
pp. 371 ◽  
Author(s):  
H. Nakamura

Variation in the electrophoretic banding patterns of high molecular weight (HMW) glutenin subunits of 274 hexaploid wheat (Triticum aestivum) varieties from China was examined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Twenty-seven different major glutenin HMW subunits were identified. Each variety contained 3–5 subunits and 29 different glutenin subunit patterns were segregated. Seventeen alleles were identified based on comparison of subunit mobilities with those previously found for hexaploid wheat. Chinese hexaploid wheats exhibited particular allelic variation in glutenin HMW subunit composition and this variation differed from that found in wheats from Japanese and other countries. Average Glu-1 quality scores of 274 Chinese wheat varieties in the present study have been shown to be higher than that of Japanese wheats. Considerable genetic variation in the HMW glutenin subunit compositions of the Chinese wheats was observed in the present study and previously. Alleles from Chinese hexaploid wheat varieties have not been extensively introduced into Japan and other countries. The present data may indicate possible applications of Chinese germplasm in wheat breeding programs. To improve the wheat quality, genetic variation should be attempted through the introduction of genes of Chinese varieties into varieties in Japan and other countries.


2000 ◽  
Vol 51 (6) ◽  
pp. 673 ◽  
Author(s):  
H. Nakamura

The endosperm storage proteins of 174 Japanese wheat (Triticum aestivum) landraces were fractionated by sodium dodecyl sulfate polyacrylamide gel electrophoresis to determine their high-molecular-weight (HMW) glutenin subunit composition. These are alleles for complex gene loci, Glu-A1, Glu-B1, and Glu-D1, that are present in Japanese hexaploid wheat landraces. These were identified by comparison with the subunit mobility previously found in hexaploid wheat. Twenty-four different, major glutenin HMW subunits were identified. Each landrace contained 3–5 subunits, and 17 different glutenin subunit patterns were observed for 13 alleles in Japanese landraces. Japanese landraces showed specific allelic variation in glutenin HMW subunits, different from those in non-Japanese hexaploid wheats.


Blood ◽  
1988 ◽  
Vol 71 (5) ◽  
pp. 1268-1276 ◽  
Author(s):  
F van Iwaarden ◽  
PG de Groot ◽  
JJ Sixma ◽  
M Berrettini ◽  
BN Bouma

The presence of high-molecular weight (mol wt) kininogen was demonstrated in cultured human endothelial cells derived from the umbilical cord by immunofluorescence techniques. Cultured human endothelial cells contain 58 +/- 11 ng (n = 16) high-mol wt kininogen/10(6) cells as determined by an enzyme-linked immunosorbent assay (ELISA) specific for high-mol wt kininogen. High-mol wt kininogen was isolated from cultured human endothelial cells by immunoaffinity chromatography. Nonreduced sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that endothelial cell high-mol wt kininogen consisted of five protein bands with mol wts of 95,000, 85,000, 65,000, 46,000, and 30,000 daltons. Immunoblotting of the endothelial cell high-mol wt kininogen by using specific antisera against the heavy and light chain indicated that the 95,000-, 85,000-, and 65,000-dalton bands consisted of the heavy and light chain whereas the 46,000- and 30,000-dalton bands reacted only with the anti-light chain antiserum. Immunoprecipitation studies performed with lysed, metabolically labeled endothelial cells and monospecific antisera directed against high-mol wt kininogen suggested that high-mol wt kininogen is not synthesized by the endothelial cells. Endothelial cells cultured in high-mol wt kininogen-free medium did not contain high-mol wt kininogen. These studies indicate that endothelial cell high-mol wt kininogen was proteolytically cleaved in the culture medium and subsequently internalized by the endothelial cells. Binding and internalization studies performed with 125I-labeled, proteolytically cleaved, high-mol wt kininogen showed that endothelial cells can indeed bind and internalize proteolytically cleaved high-mol wt kininogen in a specific and saturable way.


Genome ◽  
2006 ◽  
Vol 49 (2) ◽  
pp. 181-189 ◽  
Author(s):  
H Q Wang ◽  
X Y Zhang

High-molecular-weight glutenin subunits (HMW-GSs) play an important role in the breadmaking quality of wheat flour. In China, cultivars such as Triticum aestivum 'Xiaoyan No. 6' carrying the 1Bx14 and 1By15 glutenin subunits usually have attributes that result in high-quality bread and noodles. HMW-GS 1Bx14 and 1By15 were isolated by preparative sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and used as an antigen to immunize BALB/c mice. A resulting monoclonal antibody belonging to the IgG1 subclass was shown to bind to all HMW-GSs of Triticum aestivum cultivars, but did not bind to other storage proteins of wheat seeds in a Western blot analysis. After screening a complementary DNA expression library from immature seeds of 'Xiaoyan No. 6' using the monoclonal antibody, the HMW-GS 1By15 gene was isolated and fully sequenced. The deduced amino acid sequence showed an extra stretch of 15 amino acid repeats consisting of a hexapeptide and a nonapeptide in the repetitive domain of this y-type HMW subunit. Bacterial expression of a modified 1By15 gene, in which the coding sequence for the signal peptide was removed and a BamHI site eliminated, gave rise to a protein with mobility identical to that of HMW-GSs extracted from seeds of 'Xiaoyan No. 6' via SDS-PAGE. This approach for isolating genes using specific monoclonal antibody against HMW-GS genes is a good alternative to the extensively used polymerase chain reaction (PCR) technology based on sequence homology of HMW-GSs in wheat and its relatives.Key words: wheat, HMW-GS, monoclonal antibody, immunoscreen.


1983 ◽  
Vol 211 (2) ◽  
pp. 397-404 ◽  
Author(s):  
L Heickendorff ◽  
T Ledet

Arterial basement-membrane-like material was isolated from rabbit aortic myomedial cell cultures by sonication and differential centrifugation. Isolated basement-membrane-like material was shown to be free of both cellular and matrix contaminants, on the basis of determinations of DNA, RNA, cholesterol, phosphorus and (Na+ + K+)-activated ATPase, combined with electron microscopy. Amino acid analyses showed that arterial basement-membrane-like material was composed of predominantly non-collagenous amino acids. Evaluated by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, reduced basement-membrane-like material comprised six major and about 30 minor components in the Mr range 10 000-600 000. One of the major peptides (Mr 225 000) was disulphide-linked. Periodic acid-Schiff staining of gels indicated that most high-molecular-weight components were glycoproteins. Two-dimensional gel electrophoresis resolved reduced basement-membrane-like material into more than 100 components, with pI from 5 to 7. The disulphide-linked Mr-225 000 peptide appeared heterogeneous, with pI of 5.6-6.0, and was considered to represent fibronectin. All major peptides were of non-collagenous nature, on the basis of their susceptibility to pepsin and resistance to collagenase. Purified myomedial basement-membrane-like material contained collagenous peptides, as indicated by the presence of hydroxyproline and hydroxylysine. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis of pepsin-treated and reduced basement-membrane-like material revealed five high-molecular-weight collagenous components appearing in the Mr range 105 000-375 000 relative to type I collagen standards.


Sign in / Sign up

Export Citation Format

Share Document