首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
3.
Neutral histone-hydrolyzing protease has been isolated by fractionation of bovine spleen extract. The low level of the protease activity in the extract may be due to the presence of an inhibitor. The enzyme activity was increased 100--1200-fold during ammonium sulfate fractionations, gel filtration on Sephadex G-100 and G-75, chromatography on CM- and DEAE-celluloses. The protease was detected in the fraction with a molecular weight lower than 25000. The enzyme was markedly activated by dithiothreitol and EDTA and inhibited by p-chloromercuribenzoate and iodoacetic acid. It was also inhibited by N-tosyl-L-lysyl chloromethyl ketone, N-tosyl-L-phenylalanyl chloromethylketone, bovine blood serum and partially by soybean trypsin inhibitor DFP, trasylol and epsilon-amino caproic acid had no effect. Beside histone, the neutral protease hydrolyzed casein and gamma-globulin and fibrinogen in a low extent. The enzyme had no activity toward N-benzoyl-D,L-arginine p-nitroanilide, N-benzoyl-L-arginine ethyl ester and N-acetyl-L-tyrosine ethyl ester, collagen, elastin and fibrin. Some properties of the enzyme were similar to those of neutral SH-dependent proteases described by Hayashi and Lo Spalluto et al.  相似文献   

4.
A neutral SH-dependent proteinase was isolated from bovine spleen by a slight modification of the previous method (1) and its action on some natural and synthetic substrates was studied. The activity of the enzyme was increased 2000--2500-fold as compared to that of the original extract. The enzyme hydrolyzed various histones (H1, H2a, H2b, H3), casein and protamine but did not split hemoglobin, serum albumin and 14C-tryptophane-labelled total protein from chicken embryos. The enzyme possessed neither collagenolytic nor elastase activity; it did not inactivate aldolase, hexokinase, glyceraldehyde phosphate dehydrogenase and glucose-6-phosphate dehydrogenase, which makes the enzyme different from cathepsin B1 and some other previously described proteinases. The enzyme did not split BAPA, BAEE, ATEE, Boc-Ala-ONP, Leu-beta-NA and some other peptides. The molecular weight of the enzyme was found to be about 15 000.  相似文献   

5.
6.
A novel green heme protein from bovine spleen has been purified to apparent homogeneity. The visible spectrum, with unusually long wavelength absorptions due to alpha-, beta-, and gamma-porphyrin bands, the EPR g values of 6.81, 4.99, and 1.94, and the peroxidase activity are similar to those of myeloperoxidase (EC 1.11.1.7). The observed molecular mass of 57,000 daltons (established by gel permeation chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis studies) clearly distinguishes it from myeloperoxidase, as does the observed substrate specificity (e.g. oxidation of iodide but not ascorbate). Optical spectra of ferric and ferrous forms of the enzyme in the native state, complexed with ligands (CN-, CO, NO, N3-) and as the pyridine hemochromogens, are presented and compared to those of the corresponding derivatives of myeloperoxidase.  相似文献   

7.
Two glycosphingolipids with J blood group activity were found in J-positive bovine spleen. They were tentatively identified as ceramide deca- and dodecahexosides containing galactose, glucose, N-acetylgalactosamine and N-acetylglucosamine in a molar ratio of 5:3:1:1 and 6:3:2:1, respectively. Fucose was not present. Ceramide decahexosides without J activity were also found in J-negative bovine spleen. The principal component fatty acids of the J-active glycosphingolipids were saturated even-numbered long-chain acids with 16 to 24 C atoms. Their principal long-chain bases were sphingosine and dihydrosphingosine with smaller amounts of phytosphingosine. Both J-active glycosphingolipids were readily water-soluble and showed strong activity in the bovine J and in the porcine A blood group system. They exhibited no cross-reactivity in the human A system. However, a J-negative glycosphingolipid fraction - also from J-negative spleen - with shorter carbohydrate chain-length showed strong activity in the human A system.  相似文献   

8.
Ferritin was isolated from bovine spleen and used to prepare apoferritin and reconstituted ferritin. The mol. wt of bovine ferritin was 464,000 with monomer subunits about 18,000-19,500. Gel electrophoresis showed three bands each for ferritin, apoferritin and reconstituted ferritin; all stained for protein and carbohydrate. Only apoferritin failed to stain for iron. Bovine ferritin had higher concentrations of proline, threonine, and valine than equine or human ferritin. The iron:protein ratio of bovine ferritin was 0.161 and of equine ferritin was 0.192. After iron uptake by the apoferritins the iron:protein ratios were 0.186 and 0.278 for the bovine and equine ferritins, respectively.  相似文献   

9.
Antibodies to bovine spleen inhibitors I, II and III were elicited and their effect on the antiproteolytic activity of these Kunitz type inhibitors was tested. The immunoglobulins contain antibodies common to the four inhibitors in agreement with the great structural similarity of these antigens. Specific antibodies, which only react with the related inhibitor, were also isolated with the aim of localizing and quantifying these inhibitors "in vivo".  相似文献   

10.
11.
EDTA-extractable protein (EEP) is known to be a major lens membrane protein with a molecular mass in the range 32 kDa to 38 kDa, and is also known to bind to the lens membrane and phospholipid-containing liposomes in a calcium-dependent manner. Recent results (Russell, P., Zelenka, P., Martensen, J., and Reid, T.W. (1977) Curr. Eye Res. 6, 533-538) on antibody cross-reactivity have demonstrated that a 34-35 kDa component of EEP is identical to calpactin I (lipocortin II). In this study, we have identified and purified three distinct 34 kDa components of EEP (designated as EEP-34A1, EEP-34A2 and EEP-34B) from bovine lens that inhibit phospholipase A2 activity. These proteins bind to phospholipid-containing liposome and F-actin in a calcium-dependent fashion. Two-dimensional electrophoresis demonstrates that the three proteins were distinct from one another. However, immunochemical studies and one-dimensional peptide mapping indicate that EEP-34A1 and EEP-34B are very similar. Our results also indicate that EEP-34A1 is very similar to calpactin II and that EEP-34A2 corresponds to calpactin I. The bovine lens 34-35 kDa component of EEP is a mixture of proteins rather than a single protein.  相似文献   

12.
Two acid RNases were purified from bovine spleen by means of ammonium sulfate fractionation, chromatographies on-phospho-cellulose, heparin-Sepharose CL-6B, poly G-Sepharose, and 2', 5'-ADP-Sepharose, and gel filtration on Toyopearl HW 55F. Both purified preparations were homogeneous as judged by disc electrophoresis at pH 4.3. They were designated as RNase BSP1 and RNase BSP2 in the order of elution from a phospho-cellulose column. RNase BSP2 was immunologically indistinguishable from RNase K2 from bovine kidney. RNase BSP1 was a typical pyrimidine base-specific, uridylic acid-preferential RNase and had very sharp pH optimum at 6.5. RNase BSP1 thus obtained was a glycoprotein giving two major bands on SDS-slap electrophoresis. Although the apparent molecular weight of RNase BSP1 was distributed in the range of 27,000-20,000, it decreased to about 17,000-18,000 after endoglycosidase F digestion. The N-terminal amino acid sequence up to the 20th amino acid had no homology to those of RNase K2 and RNase A.  相似文献   

13.
We have separated three distinct 32-kDa calcium/phospholipid-regulated proteins from bovine spleen, which we have designated as 32kDa-Ia, 32kDa-Ib and 32kDa-II. By one-dimensional peptide mapping and chromatographic behavior, the three proteins are distinct from each other. Gizzard 35kDa calcimedin antibody recognizes both 32kDa-Ia and 32kDa-II but not 32kDa-Ib. Anti-aorta endonexin II specifically reacts with 32kDa-II. Bovine lens endonexin antibody reacts with 32kDa-Ia and 32kDa-Ib, but not with 32kDa-II. These data suggest that the 32-kDa calcium/phospholipid-regulated proteins purified from various sources can be divided into three distinct classes of proteins.  相似文献   

14.
In the present study, three extremely minor but novel Chol-1 antigens, termed X1, X2, and X3 have been isolated from bovine brain gangliosides. Based on the results of sialidase degradation, TLC-immunostaining with anti-Chol-1 antibody and fast atom bombardment mass spectrometry, their chemical structures were identified as: $$\begin{gathered} III^6 NeuAc--GgOse4Cer (X1:GM1\alpha ) \hfill \\ III^6 NeuAc,II^3 NeuAc--GgOse4Cer (X2:GT1a\alpha ) \hfill \\ III^6 NeuAc,II^3 NeuAc--NeuGc--GgOse4Cer (X3:GT1b\alpha ) \hfill \\ \end{gathered} $$ The yields of GM1α, GD1aα, and GT1bα, were approximately 150, 20, and 10 µg, respectively, from 10 g of the bovine brain ganglioside mixture. In conjunction with our previous observations, all gangliosides with anti-Chol-1 reactivity were found to contain a common sialyl α2–6N-acetylgalactosamine residue, indicating that this unique sialyl linkage is the specific antigenic determinant. We subsequently examined the biosyntheses of the three novel Chol-1 gangliosides using rat liver Golgi fraction as an enzyme source. The results showed that GM1α, GD1aα, and GT1bα were synthesized from asialo-GM1, GM1a, and GD1b, respectively, by the action of a GalNAc α2-6sialyltransferase.  相似文献   

15.
Complementary DNAs for the G protein alpha subunits Gi alpha 1, Gi alpha 2, Gi alpha 3, and Go alpha were expressed in Escherichia coli, and the four proteins were purified to homogeneity. The recombinant proteins exchange and hydrolyze guanine nucleotide, are ADP-ribosylated by pertussis toxin, and interact with beta gamma subunits. The rates of dissociation of GDP from Gi alpha 1 and Gi alpha 3 (0.03 min-1) are an order of magnitude slower than that from rGo alpha; release of GDP from Gi alpha 2 is also relatively slow (0.07 min-1). However, the values of kcat for the hydrolysis of GTP by rGo alpha and the three rGi alpha proteins are approximately the same, about 2 min-1 at 20 degrees C. The recombinant proteins restore inhibition of Ca2+ currents in pertussis toxin-treated dorsal root ganglion neurons in response to neuropeptide Y and bradykinin, indicating that the proteins can interact functionally with all necessary components of at least one signal transduction system. The two different receptors function with different arrays of G proteins to mediate their responses, since all four G proteins restored responses to bradykinin, while Gi alpha 2 was inactive with neuropeptide Y. Despite these results, high concentrations of activated Gi alpha proteins are without effect on adenylyl cyclase activity, either in the presence or absence of forskolin or Gs alpha, the G protein that activates adenylyl cyclase. These results are consistent with the hypothesis that G protein beta gamma subunits are primarily responsible for inhibition of adenylyl cyclase activity.  相似文献   

16.
Summary The availability of small-diameter blood vessels remains a significant problem in vascular reconstruction. In small-diameter blood vessels, synthetic grafts resulted in low patency; the addition of endothelial cells (EC) has clearly improved this parameter, thereby proving the important contribution of the cellular component to the functionality of any construct. Because the optimal source of cells should be autologous, the adaptation of existing methods for the isolation of all the vascular cell types present in a single and small biopsy sample, thus reducing patient’s morbidity, is a first step toward future clinical applications of any newly developed tissue-engineered blood vessel. This study describes such a cell-harvesting procedure from vein biopsy samples of canine and human origin. For this purpose, we combined preexisting mechanical methods for the isolation of the three vascular cell types: EC by scraping of the endothelium using a scalpel blade, vascular smooth muscle cells (VSMC), and perivascular fibroblasts according to the explant method. Once in culture, cells rapidly grew with the high level of enrichment. The morphological, phenotypical, and functional expected criteria were maintained: EC formed cobblestone colonies, expressed the von Willebrand factor, and incorporated acetylated low-density lipoprotein (LDL); VSMC were elongated and contracted when challenged by vasoactive agents; perivascular fibroblasts formed a mechanically resistant structure. Thus, we demonstrated that an appropriate combination of preexisting harvesting methods is suitable to isolate simultaneously the vascular cell types present in a single biopsy sample. Their functional characteristics indicated that they were suitable for the cellularization of synthetic prosthesis or the reconstruction of functional multicellular autologous organs by tissue engineering.  相似文献   

17.
A protease with kininogenase activity at pH 7.5 was isolated from bovine spleen extract by gel filtration and ion exchange chromatography. The protease was found in the fraction with molecular weight lower than 25.000 and was separated from the other neutral SH-dependent protease by chromatography on KM-cellulose. The kininogenase activity was inhibited by DFP and trasylol; soybean trypsin inhibitor had no effect. The protease did not split N-benzoyl-L-arginine ethyl ester and N-benzoyl-D, L-arginine p-nitroanilide.  相似文献   

18.
A melibiose-binding protein was isolated from human spleen by serial affinity chromatography on lactose-, mannose-, and melibiose-Sepharose. The purified protein agglutinated rabbit erythrocytes and re-bound to melibiose, but did not bind to murine nor human laminin. The protein was composed of 58 kDA, 32 kDa and 26 kDa polypeptides. The polypeptides were detected in buffy coat cell extracts and they were synthesizedin vitro by B lymphoblastoid cells. The polypeptides did not react with anti-galaptin, anti-C-reactive protein, anti-amyloid P, anti-keratin, and anti-rat lung lectin 29 sera. The 58 kDa polypeptide reacted very weakly with anti-core-specific lectin serum and reacted with anti-IgG serum. The data suggest that the major protein isolated is an anti-Gall 6 immunoglobulin.Abbreviations ME mercaptoethanol - PMSF phenylmethylsufonyl fluoride - HEPES 4-(2-hydroxyethyl)-1-piperazine ethanosulfonate - PBS 0.01m PO4, 0.12m NaCl, pH 7.3 - TBS 0.1m NaCl, 0.05m Tris, 0.05% NaN3, 0.01m CaCl2, 0.001m MgCl2, pH 7.3 - BSA bovine serum albumin - GSI Griffonia simplicifolia I - SDS-PAGE sodium dodecylsulfate-polyacrylamide gel electrophoresis  相似文献   

19.
20.
Isolation of spleen chalones from the postmicrosomal supernatant is described. Two glycoprotein fractions homogeneous on polyacrylamide-gel electrophoresis were obtained. In the biological test on mice, the preparation of 38 000 mol. wt. inhibited mitosis in spleen cells, and the low-molecular fraction (2100 mol. wt.) in thymus cells, showing respectively the properties of chalones B and T.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号