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1.
The haemolymph of Acrididae causes haemagglutination of human and animal erythrocytes. Thirteen of seventeen species tested had detectable activity and gave agglutination titres in the range 2–64, Melanoplus bivittatus, and M. sanguinipes showed greatest activity. Haemagglutinin activity is continuously present in male and female insects from 4th instar and throughout adulthood. Females contain slightly more activity than do males. M. sanguinipes haemolymph agglutinates rabbit, calf, human (all ABO types) guinea pig, mouse, chicken, cat, pig and sheep erythrocytes. Rabbit red cells are agglutinated most strongly and sheep and chicken cells least. M. sanguinipes haemolymph also agglutinates the protozoan Nosema locustae, a natural grasshopper pathogen. Preabsorption of haemolymph with different erythrocyte types selectively removes haemagglutinin activity suggesting the presence of multiple or heteroagglutinins. M. sanguinipes haemagglutinin is inhibited by glycoproteins, simple carbohydrates and carbohydrate derivatives. The inhibitory pattern is complex and among the sugars tested only mannose and derivatives of mannose are exclusively non-inhibitory. Haemolymph haemagglutinin activity is destroyed by heat and EDTA. It is totally precipitated by dialysis against water and may be partially recovered in phosphate or Tris buffer. Activity is stable in frozen haemolymph.  相似文献   

2.
Entomopoxvirus (EPV) occlusion bodies isolated from Arphia conspersa and Melanoplus sanguinipes grasshoppers were fed to 3rd and 4th instar Locusta migratoria nymphs. Locus mortality induced by A. conspersa EPV was first detected 18 days after addition of virus to the diet, and reached a level of approximately 68% of the colony population by 60 days after virus inoculation. In a similar population of L. migratoria nymphs, mortality induced by M. sanguinipes virus reached 90% 60 days after virus inoculation. Entomopoxvirus was isolated from M. sanguinipes EPV infected locust nymphs and the viral DNA was cleaved with several restriction endonucleases. The DNA fragment patterns obtained after agarose gel electrophoresis were compared with the fragment patterns from the original sample of M. sanguinipes EPV DNA cleaved with the same restriction endonucleases. No differences in the cleavage patterns were detected between the two virus DNA samples. Virus structural proteins of M. sanguinipes EPV purified from infected locust nymphs were compared by polyacrylamide gel electrophoresis with virus proteins isolated from the original sample of M. sanguinipes EPV. A total of six different virus protein bands were detected between the two poxvirus preparations.  相似文献   

3.
Rabbit antiserum was raised against potassium-independent asparaginase purified from Lupinus polyphyllus. A survey of 54 lines of Lupinus showed that only 11 contained the enzyme in maturing cotyledons with activities > 0.5 μmol/hr per g fr. wt. Potassium-dependent asparaginase activity was detected in a number of the remaining varieties.  相似文献   

4.
The marine red alga Georgiella confluens collected from Mackellar Inlet, King George Island, South Shetland Islands, Antarctic, was used in the isolation of a protein with agglutinating activity. The Georgiella confluens haemagglutinin (GCH) was extracted with 20 mM phosphate buffer, pH 7.0, and purified through ion exchange chromatography, followed by affinity chromatography on immobilized porcine stomach mucin. Among the erythrocytes analysed (human A, B and O groups, rabbit and chicken), GCH agglutinated specifically chicken erythrocytes. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis of the haemagglutinin revealed a single band of 21.5 kDa, while by gel filtration on Sephadex G-100 its native molecular mass was 25.5 kDa, suggesting that GCH is a monomeric protein. Haemagglutination studies showed that the GCH activity was stable through temperature variations and did not exhibit divalent cation dependence. Furthermore, the haemagglutinin was inhibited by the complex glycoproteins of porcine stomach mucin and fetuin, whereas the mono-, di-, and trisaccharides tested showed no effect.  相似文献   

5.
Analysis showed that the organic part of the chicken's egg shell consisted of a series of proteins and polysaccharides, probably present as glycoproteins and glycosaminoglycans. A purified preparation of a glycosaminoglycan (minimum mol. wt. 25 000), homogeneous by sedimentation velocity analysis and sedimentation to equilibrium in a density gradient, contained equimolar amounts of N-acetylglucosamine (36.3% w/w) and glucoronic acid (35.6% w/w). Digestion with testicular and streptomyces hyaluronidases and identification of the degradation products showed the glycosaminoglycan to be hyaluronic acid.  相似文献   

6.
《Developmental biology》1986,117(1):277-285
The enzyme β-1,3-glucanase is contained in the unfertilized eggs of most species of sea urchin. In some species, including Lytechinus variegatus, there is also substantial activity following gastrulation, and during remaining larval development. To determine if the same form of β-1,3-glucanase is present in both unfertilized eggs and after gut differentiation, an affinity purification procedure was utilized to isolate enzyme from unfertilized Lytechinus eggs. β-1,3-Glucanase is a 70,000-Da protein in this species, similar to the molecular weight of enzyme isolated from Strongylocentrotus purpuratus. Purified enzyme was used to generate an antibody that specifically recognized a 70,000-Da protein in unfertilized eggs by Western blot analysis, and stained the cortical granules of unfertilized eggs by immunofluorescence. The antibody also specifically immunoprecipitated β-1,3-glucanase activity from egg sonicates. The antibody was used to demonstrate that the form of β-1,3-glucanase present following gastrulation is antigenically distinct from the egg form. The 70,000-Da protein recognized by the antibody was no longer present by 24 hr, but embryos of this and later stages contained substantial amounts of activity, indicating the enzyme at these stages differs from the egg-specific form. In addition, the antibody was not capable of immunoprecipitating enzyme activity from pluteus sonicates. β-1,3-Glucanase has been partially purified from pluteus stage embryos, and appears to be a complex of approximately 200,000 Da. The enzyme is specific to endoderm and appears following differentiation of the gut, suggesting that it may function in larval digestion.  相似文献   

7.
1. Four polypeptide fragments, obtained by cyanogen bromide treatment of the protein flagellin from Salmonella adelaide, were tested for their antigenic activity by using them as inhibitors in three different assays: bacterial immobilization, haemagglutination of sensitized erythrocytes and quantitative micro precipitation. Immunodiffusion studies were also performed on the protein fragments. 2. Cleavage of the flagellin molecule in this way gave no detectable loss of antigenic determinants. Fragment A (mol.wt. 18000), the largest of the polypeptides, contained all the antigenic specificities present on flagellin that were recognized by the antisera used. In one test, fragment B (mol.wt. 12000) also contained antigenic activity to an extent not easily explainable by contamination with fragment A. Fragments C (mol.wt. 5500) and D (mol.wt. 4500) appeared to be antigenically inactive.  相似文献   

8.
Arginine decarboxylase (EC 4.1.1.19) has been purified and characterized from Brassica campestris cv B-9. The enzyme was purified 1120 fold and the recovery was 9%. The mol wt of the enzyme determined by gel filtration was 240 kD with identical subunits of 60 kD. The pH and temperature optima for the enzyme were 8.0 and 30°C respectively. The Km was 0.31mM. Polyamines inhibited the enzyme activity significantly. Immunodiffusion with ADC-specific antibodies showed cross reactivity against purified ADC from Brassica.  相似文献   

9.
The catechol 1,2-dioxygenase of Rhizobium leguminosarum biovar viceae USDA 2370 was purified 296-fold, yielding a homogeneous preparation with a specific activity of 51.1 U mg of protein-1. The molecular weight of the native protein was 70,000, with two identical subunits of 34,500 and 1 g-atom of iron per mol. The optimum pH for catalytic activity was 9.0 to 9.5.  相似文献   

10.
A K99-variant of Escherichia coli B41 was produced by growing the parent strain in the presence of antiserum to E. coli K12K99. Two mannose-resistant and eluting (MRE) haemagglutinins with molecular weights greater than 20 x 10(6) were extracted from the cell surface of the variant. One was an anionic antigen, partially purified by ammonium sulphate and isoelectric point precipitation, which adhered to calf intestinal brush borders; it was a protein composed of subunits with mol. wt 34000. Electron microscopy showed that this material did not have a regular fimbrial appearance, but contained some fine fibrillar structures. A second MRE haemagglutinin which was also partially purified by ammonium sulphate precipitation, had a definite fimbrial structure, being a protein composed of two subunits of mol. wt 49500 and 48000. This antigen was probably responsible for the fimbrial appearance of the K99-variant, but it was antigenically distinct from the anionic adhesin and did not adhere to calf intestinal brush borders.  相似文献   

11.
Chemical analysis of leaves from 12 different localities of Encelia farinosa (including var. phenicodonta and var. radians) collected on the peninsula of Baja California (Mexico) revealed the presence of various chemotypes that differed with regard to the concentrations of chromenes and sesquiterpene lactones. Localities of E. farinosa collected in the northern part of Baja California were characterized by high concentrations of the chromene encecalin (up to 252 μmol g−1 dry wt.), whereas the sesquiterpene lactone farinosin was not detected. Localities of E. farinosa collected at the southern tip of the peninsula lacked encecalin, but were shown to accumulate farinosin (up to 85 μmol g−1 dry wt.) instead. On the mainland of Mexico, as well as in Arizona (U.S.A.), farinosin concentrations varied from 18 to 44 μmol g−1 dry wt. for 10 different localities analyzed. Chromenes were not detected or present only in minor amounts (up to 13 μmol g−1 dry wt.), when compared to the samples from northern Baja California. Chemical variation within localities was small when compared to variation between different localities. Accumulation of encecalin and aridity seem to coincide at least on the peninsula of Baja California, as localities of E. farinosa that receive the least amount of rainfall contained the largest amounts of encecalin in their leaves. Leaves of E. farinosa that contained sufficiently large amounts of either encecalin or farinosin were both detrimental to neonate larvae of the polyphagous pest insect Spodoptera littoralis as shown by addition of the respective crude leaf extracts to artificial diet. Possible advantages of the observed intraspecific chemical variability of E. farinosa with regard to adaptation by generalist insect herbivores are discussed.  相似文献   

12.
The respiratory chain-linked external NADH dehydrogenase has been isolated from Candida utilis in highly purified form. The enzyme is soluble and has a molecular weight of approx. 1.5 · 106. The enzyme contains two moles of FMN per mole of enzyme and is composed of two large subunits of mol. wt. 270 000 and eight smaller subunits of mol. wt. 135 000. Iron and copper are present in the preparations, but appear to be contaminants. The enzyme catalyzes the oxidation of NADH and NADPH at nearly equal rates and reacts readily with 2,6-dichlorophenolindophenol, CoQ6 and CoQ1 derivatives as acceptors. Rotenone (10?5 M) and seconal (10?3 M) do not inhibit enzymatic activity.  相似文献   

13.
A soluble methane monooxygenase (sMMO: EC 1.14.13.25) was purified from a type II obligate methanotroph, Methylocystis sp. M. Ion exchange chromatography elution separated the sMMO into three components, I, II, and III. Components II and III were purified to homogeneity and were essential for the sMMO activity. Components II and III had molecular masses of approximately 233,000 and 39,000, respectively. Component II consisted of three subunits with molecular masses of 55,000, 44,000, and 21,000, which appeared to be present in stoichiometric amounts, suggesting a (αβγ)2 configuration in the native protein. Component II contained 1–4 mol of iron and was considered to be a hydroxylase. Component III was a flavoprotein, which contained 1 mol of FAD as well as 1–2mol of iron. It catalyzed the reduction of K3Fe(CN)6 and 2,6-dichloroindophenol by NADH. Component I, which was partially purified and not essential for sMMO activity, stimulated the activity by about 11-fold. Its stimulation could be replaced by addition of Fe2+. The molecular mass of the partially purified component I was estimated to be from 35,000 to 40,000 based on gel filtration, which suggested the presence of a new type of regulatory protein of sMMO.  相似文献   

14.
S-adenosylmethionine synthetase from wheat embryos was purified to electrophoretic homogeneity. The mol wt of the enzyme was 174,000 as determined by molecular sieve chromatography on Sephacryl S-200. A single subunit of purified AdoMet synthetase was observed on SOS-PAGE with a mol wt of 84,000 suggesting that the enzyme is a homodimer. The apparent Km of purified enzyme with ATP and methionine is 80 μM and 100 μM, respectively. The pH optimum of the enzyme is 7.75. The enzyme requires MgCb, KCI and reduced glutathione for optimum activity. The 3H-labelled putative S-adenosylmethionine reaction product was converted into 3H-labelled 5′-methyl-thioadenosine by heat treatment (100°C, 10 min, pH 7.0). This proved the authenticity of the reaction product of the AdoMet synthetase in wheat embryos.  相似文献   

15.
NADP-dependent glyceraldehyde 3-phosphate dehydrogenase fromEuglena gracilis (EC 1.2.1.13 [EC] ) was purified about 170-fold bya two-step procedure involving DEAE-SH cellulose chromatographyand affinity chromatography on ADP-Sepharose. The homogeneousenzyme from mildly sonicated cells contained equal amounts oftwo types of subunits with mol wts of 34,000 (A) and 38,000(B). The active enzyme had a mol wt 144,000 and is thereforean A2B2 tetramer. Enzyme from strongly sonicated Euglena cellscontained, in addition, a second allomer with a probable A4structure. NADdependent glyceraldehyde 3-phosphate dehydrogenase,a tetramer with 36,000 mol wt subunits, was unrelated immunologicallyto the NADP-dependent enzyme although the latter also showedminor NAD-dependent activity. Both isoenzymes of the NADPlinkedglyceraldehyde 3-phosphate dehydrogenase, however, were immunologicallyidentical. 1Dedicated, to Prof. Dr. O. H. Volk on his 80th birthday. (Received October 13, 1982; Accepted March 21, 1984)  相似文献   

16.
17.
New actin-binding proteins from Dictyostelium discoideum   总被引:22,自引:3,他引:19       下载免费PDF全文
Dictyostelium discoideum contains a soluble actin-binding protein that caps actin filaments at their fast growing ends. The purified protein consists of two subunits with 34 kd and 32 kd apparent mol. wts. Like similar proteins from Acanthamoeba and bovine brain the capping protein from D. discoideum acts in a Ca2+ -independent manner. It lacks severing activity as indicated by its inability to disrupt the stress fibers and the microfilament network in detergent-extracted cells. Two actin-binding proteins from a plasma membrane-enriched fraction were labeled with [125I]actin using a gel overlay technique. One of these proteins, with an apparent mol. wt. of 17 kd in SDS-polyacrylamide gels, has been purified from high-salt extracts, the other protein with an apparent mol. wt. of 31 kd has been purified from Triton X-100 extracted membranes. Monoclonal antibodies were raised against D. discoideum severin, α-actinin, the larger subunit of the capping protein, and the 17-kd membrane-associated protein. Immunoblotting of proteins from whole cell lysates showed that all these actin-binding proteins were present in both growth phase and aggregation-competent cells.  相似文献   

18.
When tested as activators on the trehalose phosphate synthetase [UDP-d-glucose:d-glucose 6-phosphate α-d-glucosyltransferase, EC 2.4.1.15 (46)] from Mycobacterium smegmatis, heparin was the best, various other sulfated polysaccharides (especially chondroitin 4- and 6-sulfates, dermatan sulfate, heparan sulfate, and γ-carrageenan) and polynucleotides were good, but hyaluronic acid, d-galacturonan, dextran sulfate, and keratan sulfate, were poor. Digestion of chondroitin sulfate with hyaluronidase destroyed the activating ability, but separation of the digestion products on Sephadex G-100 resin gave large-molecular-weight componentns that still showed activating ability. A sulfated tetra- or octa-saccharide isolated from chondroitin sulfate did not activate the enzyme, nor did they prevent the activation by chondroitin sulfate, suggesting that these small polyanions do not bind to the enzyme. Among polycations, poly-dl-ornithine (mol. wt. 15,600 daltons) was the best inhibitor of the enzyme followed by poly-l-lysine (mol. wt. 4,000 daltons), poly-d-lysine (mol. wt. 70,000 daltons), poly-d,l-lysine (mol. wt. 35,000 daltons), and then poly-l-ornithine (mol. wt. 120,000 daltons); polyglycine, polyleucine, and polyhistidine showed no effect. In all cases, more polycation was required to inhibit the enzyme when heparin was used as the activator than when chondroitin sulfate was used. The order of mixing of various reaction components was important for the extent of inhibition, the greates inhibition being observed when polyanion and polycation were mixed before the addition of enzyme, and the smallest when polyanion and enzyme were mixed before the addition of polycation.  相似文献   

19.
Extraordinary high levels of cGMP activity were detected in the fruits of Evodia rutaecarpa and E. officinalis. The mature fresh fruits contained a cGMP-like substance in concentrations ranging from 10 to 35 mmol/g dry wt, as determined by both a competitive binding assay and radioimmunoassay. The partially purified cGMP-like substance from E. rutaecarpa showed the same chromatographic properties (TLC and columns) as authentic cGMP and was decomposed by cyclic nucleotide-specific phosphodiesterase.  相似文献   

20.
High levels of cyclic AMP activity were detected in the fruit of Zizyphus jujuba. The partially purified cyclic AMP-like substance was found in amounts ranging from 100 to 150 nmol/g (fr. wt) by both a competitive binding assay and radioimmunoassay. The cyclic AMP-like substance also showed the same elution pattern as authentic cyclic AMP and was decomposed by cyclic nucleotide-specific phosphodiesterase.  相似文献   

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