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1.
Elizabeth A. Bray Satoshi Naito Nai-Sui Pan Edwin Anderson Philip Dubé Roger N. Beachy 《Planta》1987,172(3):364-370
Soybean (Glycine max (L.) Merr.) seeds contain the storage protein -conglycinin, encoded by a multigene family. -Conglycinin consists of three subunits; , , and . A genomic clone for a -subunit of -conglycinin has been characterized by restriction-enzyme mapping and hybrid selected in-vitro translation followed by immunoprecipitation. In order to determine the developmental regulation of this -subunit gene, its expression was studied in seeds of transgenic petunia (Petunia hybrida) and tobacco (Nicotiana tabacum L.) plants. The -subunit expressed in seeds of petunia and tobacco was recognized by anti--conglycinin serum at a relative molecular mass of 53 000, equivalent to that of the native protein. Separation of the petunia-seed proteins by isoelectric focusing followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot analysis showed that multiple isoelectric forms of the -subunit were produced. There was approximately a twofold variation in the accumulation of the -subunit protein in the mature seeds of transgenic petunia plants, each containing a single -subunit gene. However, the level of protein accumulation in mature seeds and the amount of -subunit mRNA in developing seeds was not correlated. Accumulation of the -subunit protein in transgenic seeds was less than the -subunit protein that accumulated in transgenic petunia seeds containing a single -subunit gene and less than the amount of the -subunit in mature soybean seeds which contain 8–13 -subunit genes. In transgenic tobacco plants, the accumulation of the -subunit protein in seeds was generally well correlated with the number of genes that were incorporated in the different transformants.Abbreviations kb
kilobase
- kDa
kilodalton
- Mr
relative molecular mass
- SDS-PAGE
sodium dodecyl sulfate polyacrylamide gel electrophoresis 相似文献
2.
A -amylase (EC 3.2.1.2) was identified in the outer pericarp (P) of developing seeds of wheat (Triticum aestivum L.) and compared with the well known -amylase which is synthesized during seed development in the starchy endosperm (E). The enzyme P already exists in the tissues before anthesis and vanishes at the time when E starts to accumulate. The isoelectric-focusing patterns of P and E are very similar. The relative molecular weight (Mr) of P is slightly higher than that of E (66 and 64.5 kDa, respectively). Both P and E exhibit common epitopes in addition to epitopes specific for each of them. The two enzymes were identified in small amounts in the green tissues of the developing seeds (inner pericarp and testa). No antigenic difference was detected between P and the -amylases of roots and leaves.Abbreviations
P
pericarp -amylase
-
E
endosperm -amylase
- IS1
anti--amylase immune serum
- IS2
anti- and anti- amylase immune serum
- IS3
anti- amylase immune serum
- IEF
isoelectric focusing
- IgG
immunoglobulin G
The authors thank Dr. P. Ziegler (Universität Bayreuth, FRG) for stimulating discussion and for useful suggestions during the writing of the text. The authors thank Miss C. Mayer for her skillful technical assistance. 相似文献
3.
Two extracellular -glucosidases (cellobiase, EC 3.2.1.21), I and II, from Aspergillus nidulans USDB 1183 were purified to homogeneity with molecular weights of 240,000 and 78,000, respectively. Both hydrolysed laminaribiose, -gentiobiose, cellobiose, p-nitrophenyl--L-glucoside, phenyl--L-glucoside, o-nitrophenyl--L-glucoside, salicin and methyl--L-glucoside but not -linked disaccharides. Both were competitively inhibited by glucose and non-competitively (mixed) inhibited by glucono-1,5-lactone. -Glucosidase I was more susceptible to inhibition by Ag+ and less inhibited by Fe2+ and Fe3+ than -glucosidase II. 相似文献
4.
Transforming growth factors 1 and2 (TGF-1 and2), tested in a clonogenic assay against primary cells from human tumors, suppress proliferation to different extents. In nineteen of twenty-six cell cultures, proliferation was < 50% of control with factor at 0.04 or 0.4 nM. Of these, TGF- 2 was more active than TGF-1 in fourteen; and TGF-1 was more active than TGF-2 in five. In seven of the nineteen, proliferation was 0% with one or the other factor. In contrast, cisplatin was much less effective in inhibiting proliferation of some of the same cells even at 1,000 or more times the molar concentration of the factors. Surprisingly, when TGF- 1 and TGF-2 were combined at equal concentrations, the antiproliferative effect of one was cancelled or markedly inhibited by the other. 相似文献
5.
F. Han S. E. Ullrich S. Chirat S. Menteur L. Jestin A. Sarrafi P. M. Hayes B. L. Jones T. K. Blake D. M. Wesenberg A. Kleinhofs A. Kilian 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1995,91(6-7):921-927
Genetic study of -glucan content and -glucanase activity has been facilitated by recent developments in quantitative trait loci (QTL) analysis. QTL for barley and malt -glucan content and for green and finished malt -glucanase activity were mapped using a 123-point molecular marker linkage map from the cross of Steptoe/Morex. Three QTL for barley -glucan, 6 QTL for malt -glucan, 3 QTL for -glucanase in green malt and 5 QTL for -glucanase in finished malt were detected by interval mapping procedures. The QTL with the largest effects on barley -glucan, malt glucan, green malt -glucanase and finished malt glucanase were identified on chromosomes 2,1,4 and 7, respectively. A genome map-based approach allows for dissection of relationships among barley and malt glucan content, green and finished malt -glucanase activity, and other malting quality parameters. 相似文献
6.
The crystal structure of mitochondrial F1-ATPase indicatesthat the and subunits fold into a structure defined by threedomains: the top -barrel domain, the middle nucleotide-binding domain,and the C-terminal -helix bundle domain (Abraham et al.1994); Bianchet et al., 1998). The -barrel domains of the and subunits form a crown structure at the top ofF1, which was suggested to stabilize it (Abraham et al.1994). In this study. the role of the -barrel domain in the and subunits of the yeast Saccharomyces cerevisiae F1,with regard to its folding and assembly, was investigated. The -barreldomains of yeast F1 and subunits were expressedindividually and together in Escherichia coli. When expressedseperately, the -barrel domain of the subunit formed a largeaggregate structure, while the domain of the subunit waspredominately a monomer or dimer. However, coexpression of the -barreldomain of subunit domain. Furthermore, the two domains copurified incomplexes with the major portion of the complex found in a small molecularweight form. These results indicate that the -barrel domain of the and subunits interact specifically with each other and thatthese interactions prevent the aggregation of the -barrel domain of the subunit. These results mimic in vivo results and suggest thatthe interactions of the -barrel domains may be critical during thefolding and assembly of F1. 相似文献
7.
Tatiana D. Vassilevskaia Cândido Pinto Ricardo Claudina Rodrigues-Pousada 《Plant molecular biology》1993,22(4):715-718
Genomic -Dash library constructed from Lupinus albus nuclear DNA was screened using a fragment of the -tubulin cDNA ( 8–31) clone of Chlamydomonas reinhardtii as probe. One of the positive recombinant phages was isolated, subcloned and analysed by sequencing. We present here nucleotide and derived amino acid sequences of the -tubulin gene, designated as L1 and identified by similarity with other -tubulins. The L1-encoded protein reveals a very high degree of similarity with other plant tubulins and contains consensus sequences for binding guanine base, phosphate and Mg2+. Northern analysis of total RNA isolated from roots, leaves, flowers and pools revealed that Lupinus albus -tubulin genes are constitutively expressed in all studied plant tissues. 相似文献
8.
Expression sites of genes encoding (13,14)--glucan 4-glucanohydrolase (EC 3.2.1.73) have been mapped in germinated barley grains (Hordeum vulgare L.) by hybridization histochemistry. A32P-labelled cDNA (copy DNA) probe was hybridized to cryosections of intact barley grains to localize complementary mRNAs. No mRNA encoding (13,14)--glucanase is detected in ungerminated grain. Expression of (13,14)--glucanase genes is first detected in the scutellum after 1 d and is confined to the epithelial layer. At this stage, no expression is apparent in the aleurone. After 2 d, levels of (13,14)--glucanase mRNA decrease in the scutellar epithelium but increase in the aleurone. In the aleurone layer, induction of (13,14)--glucanase gene expression, as measured by mRNA accumulation, progresses from the proximal to distal end of the grain as a front moving away from, and parallel to, the face of the scutellum.Abbreviations cDNA
copy DNA
- RNase
ribonuclease 相似文献
9.
Cornelis H. Hokke Jos G. M. van der Ven Johannis P. Kamerling Johannes F. G. Vliegenthart 《Glycoconjugate journal》1993,10(1):82-90
Incubation of synthetic Man\1-4GlcNAc-OMe, GalNAc1-4GlcNAc-OMe, Glc1-4GlcNAc-OMe, and GlcNAc1-4GlcNac-OMe with CMP-Neu5Ac and rat liver Gal1-4GlcNAc (2-6)-sialyltransferase resulted in the formation of Neu5Ac2-6Man1-4GlcNAc-OMe, Neu5Ac2-6GalNAc1-4GlcNAc-OMe, Neu5Ac2-6Glc1-4GlcNAc-OMe and Neu5Ac2-6GlcNAc1-4GlcNAc-OMe, respectively. Under conditions which led to quantitative conversion of Gal1-4GlcNAc-OEt into Neu5Ac2-6Gal1-4GlcNAc-OEt, the aforementioned products were obtained in yields of 4%, 48%, 16% and 8%, respectively. HPLC on Partisil 10 SAX was used to isolate the various sialyltrisaccharides, and identification was carried out using 1- and 2-dimensional 500-MHz1H-NMR spectroscopy.Abbreviations 2D
2-dimensional
- CMP
cytidine 5-monophosphate
- CMP-Neu5Ac
cytidine 5-monophospho--N-acetylneuraminic acid
- COSY
correlation spectroscopy
- DQF
double quantum filtered
- HOHAHA
homonuclear Hartmann-Hahn
- MLEV
composite pulse devised by M. Levitt
- Neu5Ac
N-acetylneuraminic acid
- Neu5Ac2en
2-deoxy-2,3-didehydro-N-acetylneuraminic acid 相似文献
10.
A -carotene oxygenase is described which occurs in the Cyanobacterium Microcystis. It cleaves -carotene and zeaxanthin specifically at the positions 7,8 and 7,8, while echinenone and myxoxanthophyll are not affected. The oxidative cleavage of -carotene leads to the formation of -cyclocitral and crocetindial and that of zeaxanthin to hydroxy--cyclocitral and crocetindial in nearly stoichiometric amounts. Oxidant is dioxygen as has been demonstrated by high incroporation (86%) of 18O2 into -cyclocitral. -Carotene oxygenase is membrane bound, sensitive to sulfhydryl reagents, antioxidants and chelating agents. Iron seems to be an essential part of the enzyme activity. Cofactors necessary for the reaction could not be detected.Abbreviations TLC
thin layer-chromatography
- PIPES
piperazine-N,N-bis-(2-ethanesulfonate) Na
- TES
2{[tris-(hydroxymethyl)-methyl]-amino} ethanesulfonic acid
Dedicated to Professor G. Drews on occasion of his 60th birthday 相似文献
11.
Endo--galactosidase (EC 3.2.1.103) ofBacteroides fragilis, at 250 mU ml–1, did not cleave the internal galactosidic linkage of the linear radiolabelled trisaccharide GlcNAc1-6Gal1-4GlcNAc, or those of the tetrasaccharides Gal1-4GlcNAc1-6Gal1-4GlcNAc and Gal1-4GlcNAc1-6Gal1-4Glc. The isomeric glycans which contained the GlcNAc1-3Gal1-4GlcNAc/Glc sequence were readily cleaved.Abbreviations GlcNAc
2-acetamido-2-deoxy-d-glucose
- Lact
lactose
- MT
maltotriose
- MTet
maltotetraose
-
R
MTet
chromatographic migration rate in relation to that of maltotetraose 相似文献
12.
Oxysterols have been shown to induce apoptosis in a variety of cell lines. The mechanism of oxysterol-induced apoptosis is mainly known at the post-mitochondrial level. The aim of the present study was to compare the pathway of apoptosis induced by the oxysterols 7-hydroxycholesterol (7-OH) and cholesterol-5,6-epoxide (-epoxide) in U937 cells. To this end, we employed a range of inhibitors of apoptosis; a broad-spectrum caspase inhibitor, a specific caspase-3 inhibitor and an inhibitor of cytochromec release and the antioxidants; trolox, ebselen and resveratrol. The three inhibitors of apoptosis prevented cell death induced by 7-OH; however, in -epoxide-treated cells, the inhibitor of cytochromec release did not protect against apoptosis. The cellular antioxidant glutathione was depleted in 7-OH-treated cells but not in cells incubated with -epoxide. Trolox, a water-soluble synthetic analogue of -tocopherol, prevented 7-OH-induced apoptosis but did not protect against cell death induced by -epoxide. Ebselen and resveratrol did not protect U937 cells against apoptosis induced by either 7-OH or -epoxide. Our results suggest that differences occur in the pathways of apoptosis induced by 7-OH and -epoxide in U937 cells. 相似文献
13.
Chorionic gonadotropin (CG) is a placental derived hormone that plays a crucial role in successful implantation and establishment of early pregnancy in the primates. The rhesus monkey was chosen as a model to understand the feasibility of developing human DNA immuno-contraceptive. The coding region of rhesus monkey CG -subunit (rmCG) was isolated by the TDRT-PCR method. The nucleotide sequence including the leader peptide was 499 nucleotide long and encoded 166 amino acids. In comparing with the previous known primates CG -subunits, the rmCG was the highest degree of homology with baboon CG -subunit at the deduced amino acid sequence (94%), 79.5% homology with human CG -subunit and 70.4% homology with marmoset monkey CG -subunit. The eukaryotic expression vector pCMV4-rmCG inserted full-coding cDNA sequence of rmCG was constructed, and the expression of rmCG -subunit in HeLa cells transient expressing system in vitro and BALB/c mice in vivo was determined. The results demonstrated that the recombinant PCMV4-rmCG eukaryotic expression vector could express rmCG -subunit in vitro and in vivo. 相似文献
14.
A vacuolar type -d-fructofuranosidase (Osfruct3) was cloned from etiolated rice seedlings cDNA library. It encodes an open reading frame of 688 residues. The deduced amino acid sequence had 58% identity to the vacuolar type -d-fructofuranosidase of maize (Ivr1). Osfruct3 exists as a single copy per genome. Northern analyses showed that Osfruct3 undergoes organ-specific expression and is involved in the adjustment of plant responses to environmental signals and metabolizable sugars. Osfruct3 was also heterologously expressed in Pichia pastoris. The recombinant proteins were confirmed to be a vacuolar type -d-fructofuranosidase. 相似文献
15.
Teruo Yoshino Minobu Sadamitsu Megumi Minagawa Gerd Reuter Roland Schauer 《Glycoconjugate journal》1988,5(4):377-384
The preparation of benzyl 2,3,6,2,6-penta-O-benzyl--d-lactoside, which is a key intermediate for chemical synthesis of oligosaccharide components of glycosphingolipids, was achieved by an improved method. The 3-O-p-methoxybenzyl and 3-O-methyl derivatives were prepared from benzyl 2,3,6,2,6-penta-O-benzyl--d-lactoside through stannylation. By using benzyl -d-lactoside as starting material, benzyl 3-O-methyl-, 3-O-benzyl- and 3-O-p-methoxybenzyl--d-lactoside were regioselectively synthesized using the same procedure. 相似文献
16.
Glycosylation is one of the most important post-translational modifications and it is clear that the single step of -1,4-galactosylation is performed by a family of -1,4-galactosyltransferases (4-GalTs) and that each member of this family may play a distinct role in different tissues and cells. In this study, we characterized the gene expression of six 4-GalTs in mouse testis and analyzed the changes of galactosylation of testis glycoproteins during postnatal development. Northern blot analysis revealed that 4-GalT-I and 4-GalT-IV were expressed mainly in newborn mouse testis and that the expression of 4-GalT-II increased markedly and persisted at the highest levels in adult mouse testis. The expression of 4-GalT-III and 4-GalT-V, however, remained relatively at low levels during mouse testicular development. In contrast, the expression of 4-GalT-VI was undetectable in mouse testis. The gene expression of 4-GalT-II in mouse testis was further analyzed by in situ hybridization due to its unique expression pattern. Strong hybridization signals were detected in the seminiferous tubules and the expression varied among the different stages of spermatogenic differentiation. The distinct gene expression patterns of 4-GalTs in mouse testis could affect the differential galactosylation of testis glycoproteins, as revealed by lectin histochemistry analysis. 相似文献
17.
Debomoy K. Lahiri 《Cellular and molecular neurobiology》1994,14(4):297-313
Summary 1. Alzheimer's disease is characterized by the deposition in the brain of extracellular amyloid plaques and vascular deposits consisting mostly of amyloid-peptide (A). A, a polypeptide of 39–43 amino acids (M
r, 4 kDa), is derived proteolytically from a family of proteins of 695–770 amino acids (M
r, 110–140 kDa) called-amyloid precursor protein (APP).2.APP, an integral membrane glycoprotein, is extensively posttranslationally modified within the endoplasmic reticulum (ER) and various Golgi compartments.APP is cleaved by proteases in either the trans-Golgi network or the post-Golgi apparatus and then secreted as a truncated soluble form into the conditioned media of cultured cells and cerebrospinal fluid samples from human subjects.APP can be processed either by an antiamyloidogenic secretory pathway or by an endosomal/lysosomal pathway.3. I studied the effect of two ionophores on the processing ofAPP in cultured cells. Monensin and, in some cases, ammonium chloride increase the intracellular accumulation ofAPP in several cell lines and may alter its processing. Monensin, which had the most consistent effects, also inhibited secretion ofAPP in a differentiated (growth factor mediated) cell line. Nigericin, with greater K+ selectivity, was less able to alter the accumulation and possible processing of the protein.4. These results suggest that the increase in the accumulation of intracellularAPP observed after treating cells with ionophores has some specificity. The selective effect of these ionophores on the metabolism ofAPP may provide a model system to analyze the pathways for studying maturation, secretion, and degradation ofAPP. 相似文献
18.
Sova VV Shirokova NI Kusaykin MI Scobun AS Elyakova LA Zvyagintseva TN 《Biochemistry. Biokhimii?a》2003,68(5):529-533
-1,3-Glucanase (Lu) was isolated from unfertilized eggs of the sea urchin Strongylocentrotus intermedius. A comparative study of some properties of -1,3-glucanase Lu and -1,3-glucanases with different action types—endo--1,3-glucanase from crystalline style of the marine mollusk Spisula sachalinensis (LIV) and exo--1,3-glucanase from the terrestrial snail Eulota maakii (LII)—was performed. It was found that -1,3-glucanase Lu hydrolyzes laminaran with a high yield of glucose in the reaction products. The enzyme hydrolyzes substrates with retention of the glycosidic bond configuration, is able to cleave modified substrates, and exhibits transglycosylating activity. All properties of -1,3-glucanase from S. intermedius were more similar to those of the endo--1,3-glucanase from the marine mollusk (LIV) than exo--1,3-glucanase LII from the terrestrial snail. The differences in the effect of LIV and Lu on laminaran are probably related to the functions of -1,3-glucanase Lu from sea urchin eggs (which, in contrast to LIV, is not a digestive enzyme). 相似文献
19.
William Kuhns Volker Rutz Hans Paulsen Khushi L. Matta Michael A. Baker Marijke Barner Maria Granovsky Inka Brockhausen 《Glycoconjugate journal》1993,10(5):381-394
To elucidate control mechanisms ofO-glycan biosynthesis in leukemia and to develop biosynthetic inhibitors we have characterized core 2 UDP-GlcNAc:Gal1-3GalNAc-R(GlcNAc to GalNAc) 6-N-acetylglucosaminyl-transferase (EC 2.4.1.102; core 2 6-GlcNAc-T) and CMP-sialic acid: Gal1-3GalNAc-R 3-sialyltransferase (EC 2.4.99.4; 3-SA-T), two enzymes that are significantly increased in patients with chronic myelogenous leukemia (CML) and acute myeloid leukemia (AML). We observed distinct tissue-specific kinetic differences for the core 2 6-GlcNAc-T activity; core 2 6-GlcNAc-T from mucin secreting tissue (named core 2 6-GlcNAc-T M) is accompanied by activities that synthesize core 4 [GlcNAc1-6(GlcNAc1-3)GalNAc-R] and blood group I [GlcNAc1-6(GlcNAc1-3)Gal-R] branches; core 2 6-GlcNAc-T in leukemic cells (named core 2 -GlcNAc-T L) is not accompanied by these two activities and has a more restricted specificity. Core 2 6-GlcNAc-T M and L both have an absolute requirement for the 4- and 6-hydroxyls ofN-acetylgalactosamine and the 6-hydroxyl of galactose of the Gal1-3GalNAc-benzyl substrate but the recognition of other substituents of the sugar rings varies, depending on the tissue. 3-sialytransferase from human placenta and from AML cells also showed distinct specificity differences, although the enzymes from both tissues have an absolute requirement for the 3-hydroxyl of the galactose residue of Gal1-3GalNAc-Bn. Gal1-3(6-deoxy)GalNAc-Bn and 3-deoxy-Gal1-3GalNAc-Bn competitively inhibited core 2 6-GlcNAc-T and 3-sialyltransferase activities, respectively.Abbreviations AFGP
antifreeze glycoprotein
- AML
acute myeloid leukemia
- Bn
benzyl
- CML
chronic myelogenous leukemia
- Fuc
l-fucose
- Gal, G
d-galactose
- GalNAc, GA
N-acetyl-d-galactosamine
- GlcNAc, Gn
N-acetyl-d-glucosamine
- HC
human colonic homogenate
- HO
hen oviduct microsomes
- HPLC
high performance liquid chromatography
- mco
8-methoxycarbonyl-octy
- Me
methyl
- MES
2-(N-morpholino)ethanesulfonate
- MK
mouse kidney homogenate
- onp
o-nitrophenyl
- PG
pig gastric mucosal microsomes
- pnp
p-nitrophenyl
- RC
rat colonic mucosal microsomes
- SA
sialic acid
- T
transferase
Enzymes: UDP-GlcNAc:Gal1-3GalNAc-R (GlcNAc to GalNAc) 6-N-acetylglucosaminyltransferase,O-glycan core 2 6-GlcNAc-transferase, EC 2.4.1.102; CMP-sialic acid: Gal1-3GalNAc-R 3-sialyltransferase,O-glycan 3-sialic acid-transferase, EC 2.4.99.4. 相似文献
20.
Françoise Dacheux 《Cell and tissue research》1981,215(1):87-101
Summary The peroxidase-antiperoxidase immunocytochemical technique was used to identify the ACTH/endorphin cells in the porcine pituitary at the ultrastructural level and to determine the precise subcellular localization of the pro-ACTH/endorphin fragments. The cells display different aspects: 1) large, regular shapes with numerous and large secretory granules; 2) small, irregular and angular shapes with small granules aligned along the periphery of the cell; and 3) intermediate forms. The presence of and -endorphin not only in the same cells but also in the same secretory granules that contain ACTH and -LPH clearly indicates that both the precursor or its fragments and the abovementioned peptides are stored in the same granules and released simultaneously by the corticotropic cells. The presence of FSH in some corticotropic cells is also discussed.Abbreviations used in this Article
ACTH
corticotropin
-
-MSH
-melanotropin (ACTH I–I3)
-
CLIP
corticotropin-like intermediate lobe peptide (ACTH 18–39)
-
-LPH
-lipotropin
-
-MSH
-melanotropin (-LPH 41–58); -endorphin (-LPH 61–91); -endorphin (-LPH 61–76) 相似文献