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1.
Three new electrophoretic variants of human erythrocyte triosephosphate isomerase (TPI) have been partially purified and compared with the normal isozyme with respect to stability, kinetics, and immunological properties. TPI 2HR1, an anodally migrating variant, was less stable than normal in guanidine denaturation and thermodenaturation tests, although it exhibited normal kinetic properties. The level of enzyme activity in erythrocytes from the proband with the phenotype TPI 1-2HR1 was about 60% of the normal mean. The variant allozyme TPI 2NG1, an anodally migrating allozyme associated with normal activity, was very thermolabile at 55 and 57°C. It was also much more labile than normal in stability tests in buffers at pH 5 and pH 10, although it exhibited normal kinetic and immunological properties. TPI 4NG1, a cathodally migrating variant associated with normal activity and normal kinetic as well as immunological properties, was more stable than normal in pH 5 buffer. Family studies demonstrated that the unique characteristics of these variants are genetically transmitted. In two-dimensional electrophoresis of purified isozymes the variant subunits were separated from the normal in the pI axis. However, there is no difference between the variants and the normal in the molecular weight axis, suggesting that the variants result from single amino acid substitutions.  相似文献   

2.
Amylolytic enzymes of Arabidopsis leaf tissue were partially purified and characterized. Endoamylase, starch phosphorylase, d-enzyme (transglycosylase), and possibly exoamylase were found in the chloroplasts. Endoamylase, fraction A2, found only in the chloroplast, was resolved from the exoamylases by chromatography on a Mono Q column and migrated with an RF of 0.44 on 7% polyacrylamide gel electrophoresis. Exoamylase fraction, A1, has an RF of 0.23 on the polyacrylamide gel. Viscometric analysis showed that A1 has a slope of 0.013, which is same as that of A3, the extrachloroplastic amylase. A1, however, can be distinguished from A3 by having much higher amylolytic activity in succinate buffer than acetate buffer, and having much less reactivity with amylose. A1 probably is also localized in the chloroplast, and contributes to the 30 to 40% higher amylolytic activity of the chloroplast preparation in succinate than acetate buffer at pH 6.0. The high activity of d-enzyme compared to the amylolytic activity in the chloroplast suggests that transglycosylation probably has an important role during starch degradation in Arabidopsis leaf. Extrachloroplastic amylase, A3, has an RF of 0.55 on 7% electrophoretic gel and constitutes 80% of the total leaf amylolytic activity. The results of substrate specificity studies, action pattern and viscometric analyses indicate that the extrachloroplastic amylases are exolytic.  相似文献   

3.
Serum amylase variants are demonstrated by means of starch gel and polyacrylamide gel electrophoresis. Phenotypes, allele frequencies, and segregation data for Am1 and Am2 in the cattle breed Deutsche Schwarzbunte are given. Demonstration of Am2 amylases was better in polyacrylamide gels and more isoenzymes were identified than in starch gels. The variants of Am1 amylases found in STAGE could not be reproduced in PAGE by means of the described methods. Both enzyme systems seem to be profoundly different in their molecular constitution and action. For the animals, these differences could be of advantage in the adaption to external influences.  相似文献   

4.
Summary The PGM3 locus, like the PGM1 locus, is shown to be easily demonstrated in hair sheath cells using starch gel electrophoresis. The discriminating power of the total system (PGM1 and PGM3) on starch gel electrophoresis closely approaches that observed by isoelectric focusing of the PGM1 locus. Family studies of the PGM3 locus variants in hair sheath cells confirm that the alleles responsible are inherited in a Mendelian fashion independent of the PGM1 locus.  相似文献   

5.
We compared the occurrence of peroxidase isozymes in protein extract from roots, hypocotyls and cotyledons of 10 dayCucurbita pepo plants and of adult leaves of older plants by means of starch gel and polyacryl amide gel electrophoresis. We reached maximum discrimination by means of starch gel electrophoresis: 11 zones were ascertained on the cathode side and about 2 on the anode side at pH 3.1. Two zones occurred regularly:A and (the latter having a more complicated structure). ZoneD is characteristic for roots, but is it suppressed and seldom found with leaves. On the other hand zonesC 1 andC 2 are clearly discernible with leaves but are substantially less evident with roots. The character of anodic zoneZ is discussed later in this paper.  相似文献   

6.
Pepsinogen B: the zymogen of pepsin B   总被引:4,自引:4,他引:0  
1. Pepsinogen B, the precursor of pepsin B, has been isolated by ion-exchange chromatography and gel filtration from neutral extracts of pig gastric mucosa. The material possesses potential activity against acetyl-l-phenylalanyl-l-di-iodotyrosine and against gelatin but has little, if any, potential activity against haemoglobin. 2. The material appears homogeneous in the ultracentrifuge, but on gel filtration and on electrophoresis in starch gel it is shown to be contaminated with a small amount of material having potential activity against haemoglobin. On electrophoresis in starch gel also the material is shown to contain about equal amounts of two major components, both of which have potential activity against the synthetic substrate. Pepsin B has also been shown to contain two active components by electrophoresis under the same conditions. 3. The zymogen is similar to pepsinogen and pepsinogen C in its molecular weight and general physico-chemical properties, but differs from these zymogens in the nature of its N-terminal residues. It is possible that one of the components contains 1 mole of bound phosphate/mole. 4. The material is activated rapidly at pH2 and more slowly at pH4. At both pH values the kinetics of the activation reaction are complex.  相似文献   

7.
A modification of the method described by Kristjansson (1963) allows easier distinction of the components and position of every major cattle transferrin phenotype. The modification is based on increasing the percentage of starch (15%) and reducing the pH of the gel buffer to 6.8. In all the experiments, when a voltage of 350 was applied, a tray of ice was placed over the starch gel for the remainder of the electrophoresis. Different cattle transferrin phenotypes from our modified electrophoresis method are composed as follows: Type A, 4 bands; D1, 4 bands; D1D2, 4 bands; D2, 4 bands; E, 4 bands; AD1, 6 bands; AD2, 6 bands; AE, 8 bands and sometimes 9 bands; D1E, 6 bands and sometimes 7 bands; and D2E, 6 bands. The position of the fourth D band is distinctly different in D1 vs. D2 types.Journal Paper No. J-5937 of Iowa Agriculture and Home Economics Experiment Station, Ames. Project 1551.with a fellowship given by the Consejo National de Investigaciones Cientificas y Tecnicas de la Republica Argentina to work at the Department of Genetics, Iowa State University, Ames.  相似文献   

8.
This study was conducted to investigate the expression patterns of pathogenesis-related proteins (chitinase, β-1,3-glucanase and peroxidase) using activity staining of native-polyacrylamide gel electrophoresis (PAGE) and sodium dodecyl sulfate (SDS)-PAGE during germination of rape seed (Brassica napus L. cv. Saturnin). The crude enzymes were extracted by distilled water (DW, pH 6.0) and 100 mM K-PO4 buffer (pH 7.0). The expression patterns of chitinase isozymes changed clearly on 10% native-PAGE gel with DW and K-PO4 buffer extract and on 12% SDS-PAGE gel with K-PO4 buffer extract, except for 12% SDS-PAGE conducted using DW during germination. The active bands of the chitinase isozymes were observed as four major bands (ch1, ch2, 86, and 78 kDa) and three minor bands (71, 60, and 54 kDa) on 10% native-PAGE gel conducted using DW and K-PO4 buffer extract. The two active bands on the 12% (w/v) SDS-PAGE gel presented as 34 and 29 kDa with DW extract, whereas one active band of 34 kDa was observed when the K-PO4 buffer extract was used. Active bands of β-1,3-glucanase isozymes changed slightly on 10% native-PAGE gel with DW and K-PO4 buffer extract during germination. The active band of β-1,3-glucanase isozymes were shown to have a high molecular weight (G1 and G2) on native-PAGE gel with DW extract at 0, 1, 2, and 3 days after germination, but not at 4 and 5 days. One active band of β-1,3-glucanase presented as G1 in the K-PO4 buffer extract. Active staining of peroxidase was stronger earlier in the DW extract than K-PO4 buffer extract at 2 days. The active bands showed as P1 and P2 in both DW and K-PO4 buffer extract at 5 days after germination.  相似文献   

9.
等位酶淀粉凝胶电泳技术中的几个应引起重视的问题   总被引:7,自引:0,他引:7  
本文总结了我们在用淀粉凝胶电泳技术进行等位酶分析的实验过程中的一些经验和教训,主要结论是:1)尽管材料不同,对于不同的酶系统,用特定的缓冲液系统常能获得比较理想的效果,如DIA,GPI,HEX,SOD和TPI用S6(Soltis等,1983);AMP用S8;MDH用S9和SKD用W2(Wendel和Weeden,1989)等。2)用磷酸缓冲液配制AMP的染色配方较其它配方效果好。3)当胶染时,使用琼脂替代琼脂糖,染色效果不变而成本更低,谱带扩散更慢。4)不同的提取液可能适用于不同的酶系统,如磷酸PVP提取液(Soltis等,1983)不适用于石荠苎的GPI的提取。5)正确选择凝胶和电极缓冲液,S1虽然适用面广,但效果不一定好,对于位点多和等位基因丰富的材料尤其应警惕,因S1可能掩盖样品之间的差异。  相似文献   

10.
Two new electrophoretic variants of glutamic-pyruvic transaminase (GPT) have been found by polyacrylamide gel electrophoresis at acidic pH. They appeared to represent a single allele, GPT 2, by the standard method of starch gel electrophoresis. Studies in families show that they are inherited as codominant alleles at the GPT locus. Population frequencies are about the same as those of other rare GPT variants. Their behavior on gels is consistent with both of them having substitutions of histidines in place of uncharged amino acids.  相似文献   

11.
In order to clarify the actual nomenclature of the albumin allotypes in French and Italian populations we compared the samples collected in our laboratory to those kindly supplied by Dr. Porta (Italy) with reference to albumin variants classified in starch gel electrophoresis using three buffer systems by Weitkamp. The inherited human albumin variants can be classified on the basis of their relative mobilities on cellulose acetate electrophoresis compatively to human transferrin mobility. The relative mobility of each variant can be expressed by the following ratio: migration distance of the variant versus migration distance of the normal albumin where zero represents the transferrin mobility. Using three buffers system at pH 8.6, 5.0 and 6.9, it is possible to distinguish some albumin variants having a same mobility at alkaline pH and different mobilities at acidic pH. In the european area, eleven albumin variants are distinguishable on the basis of their relative mobilities at different pH: four Fast moving variants: Gent, Vanves (a new variant described here), Reading and CN/BL, and seven Slow moving variants: MI/MI Slow, GE/CT, SO/BS (or D type), Pollibauer, Gainesville, Roma and B type. Thirty-six sera from unrelated subjects with genetic bisalbuminemia were analyzed in our laboratory. Their distribution was as follows: B type (22), Pollibauer (9), SO/BS (2), Gainesville (1), Gent (1) and Vanves type (1). The frequency of bisalbuminemia was 0.35 per 1,000 in a population of 19,949 blood donors.  相似文献   

12.
Up until now it has been assumed that the protease-binding property of alpha1-protease inhibitor (alpha1PI) was destroyed by acid starch gel electrophoresis (pH 4.9). Analyses on acid starch gel blocks for pH and conductivity changes during and following a typical electrophoretic run showed that it was unlikely that the separating alpha1PI would be exposed to pH values lower than 6.2, and that the allele products, following the passage of the buffer front, were in an environment of constant pH(6.3), extremely low conductivity and high field strength. These results strongly suggested the likelihood that alpha1-PI would be chemically and physically unchanged as a result of exposure to acid starch gel electrophoresis. In order to test this likelihood, human serum was electrophoretically separated in acid starch gel and following electrophoresis, was immersed in 0.1 M diethylbarbiturate buffer, pH 8.6, containing 20 mug/ml of pancreatic elastase. The pH-adjusted (8.15) and elastase-impregnated starch gel layer was superimposed on hemoglobin-agar for 2.5 h at 37 degrees C followed by immersion of the hemoglobin-agar layer in 1% NaCl overnight, distilled water for 2 h, drying under filter paper and staining. The results showed zones of undigested hemoglobin indicating, unequivocally, that the separated alpha1PI allele products are capable of forming complexes with proteases and that alpha1PI is not inactivated following exposure to acid starch gel electrophoresis. Densitometric analysis of the transparent stained zones on a clear agar gel background offers an alternative to analysis of the acid starch gel-separated zones by antigen-antibody crossed electrophoresis and as such is suitable for identification of alpha1-protease inhibitor phenotypes. Further, the method is specific for alpha1PI and a densitometric scan provides direct information relative to the protease-binding capacity of the sample as well as the contribution of each alpha1PI allele product to that capacity.  相似文献   

13.
Summary A total of 3000 men living in Yamaguchi were screened for glucose-6-phosphate dehydrogenase (G6PD) deficiency using Beutler's spot test and three types of starch gel electrophoresis. These electrophoresis used a phosphate buffer system at pH 7.0, a TRIS-EDTA-borate buffer system at pH 8.6, and a TRIS-hydrochloride buffer system at pH 8.8. Fifteen G6PD-deficient variants were found at the rate of 0.5% and classified into four groups. As new variants, G6PD Konan, Kamiube, and Kiwa were identified. These three variants had a mild to moderate G6PD deficiency and were not associated with any clinical signs. G6PD Konan had fast electrophoretic mobility as compared with normal levels, G6PD Kiwa had slightly elevated electrophoretic mobility, and G6PD Kamiube had normal electrophoretic mobility. These three variants had normal levels of Km G6P, Km NADP, and Ki NADPH, normal utilizations of both 2-deoxy-G6P and deamino-NAPD, normal heat stability, and a normal pH curve. The other variant was G6PD Ube, which we had previously found in Yamaguchi (Nakashima et al., 1977). One boy with G6PD Ube was Korean.  相似文献   

14.
本文总结了我们在用淀粉凝胶电泳技术进行等位酶分析的实验过程中的一些经验和教训,主要结论是:1)尽管材料不同,对于不同的酶系统,用特定的缓冲液系统常能获得比较理想的效果,如DIA,CPI,HEX,SOD和TPI用S6(Soltis等,1983);AMP用S8;MDH用S9和SKD用W2(Wendel和Weeden,1989)等。2)用磷酸缓冲液配制AMP的染色配方较其它配方效果好。3)当胶染时,使用琼脂替代琼脂糖,染色效果不变而成本更低,谱带扩散更慢。4)不同的提取液可能适用于不同的酶系统,如磷酸-PVP提取液(Soltis等,1983)不适用于石荠苎的GPI的提取。5)正确选择凝胶和电极缓冲液,S1虽然适用面广,但效果不一定好,对于位点多和等位基因丰富的材料尤其应警惕,因S1可能掩盖样品之间的差异。  相似文献   

15.
1. Alkaline phosphatase of human placenta was purified by a procedure involving homogenization with tris buffer, pH8.6, extraction with butanol, ammonium sulphate fractionation, exposure to heat, ethanol fractionation, gel filtration, triethylaminoethylcellulose anion-exchange chromatography, continuous curtain electrophoresis on paper and equilibrium dialysis. Methods for both laboratory-scale and large-scale preparation were devised. 2. Two major molecular-weight variants designated A and B were separated by molecular sieving with Sephadex G-200 and variant A was purified 4000-fold. 3. Variant B, which comes off the Sephadex G-200 column before variant A, is the electrophoretically slower-moving species on starch gel and is quite heterogeneous. 4. Purified variant A was fairly homogeneous on the basis of electrophoretic studies on starch gel and Sephadex gel, ultracentrifugation and immunodiffusion. 5. The respective molecular weights for variants A and B were 70000 and over 200000 on the basis of sucrose-density-gradient ultracentrifugation. Variant A exhibited a sedimentation coefficient of 4.2s. 6. Crystalline variant B could be converted into fast-moving variant A and vice versa. 7. Kinetic studies indicated no difference between the two variants. These include linear rates of hydrolysis, pH optimum, Michaelis constants and uncompetitive stereospecific l-phenylalanine inhibition. 8. The amino acid compositions of variants A and B and of placental albumin were determined.  相似文献   

16.
Purification and preliminary characterization of human leukocyte elastasel.   总被引:1,自引:0,他引:1  
Affinity chromatography permits the purification of 1–3 mg of human leukocyte elastase from the leukocytes contained in 500 ml of whole blood. Lysosomal granule proteins are extracted from polymorphonuclear leukocytes and subjected to chromatography on a column of elastin-Sepharose. Contaminating proteins are eluted with buffer containing 1 m NaCl and then elastase activity is eluted with buffer containing 8 m urea. The enzyme retains all of its esterase activity against N-t-BOC-l-alanine p-nitrophenyl ester after exposure to 8 m urea and retains 22% of its activity in the presence of 1% sodium dodecyl sulfate. In sodium dodecyl sulfate and 2-mercaptoethanol leukocyte elastase undergoes autolysis giving rise to several low molecular weight fragments. The molecular weight of the native enzyme is found to be 22.000 by both gel filtration and sodium dodecyl sulfate—acrylamide gel electrophoresis. A characteristic set of four isozymes is seen after acrylamide disc gel electrophoresis at pH 4.5. All bands are active against elastin and also contain carbohydrate by the periodic acid-Schiff stain. On the basis of stain intensity, the slower moving isozymes appear to be richest in carbohydrate. Active leukocyte elastase forms a complex with α1-antitrypsin in a 1:1 molar ratio. The elastase must be enzymatically active for complex formation to occur.  相似文献   

17.
A study of Taka-amylase A of conidia from Aspergillus oryzae RIB40 was done. During the research, proteins from conidia and germinated conidia were analyzed using SDS–PAGE, 2-D gel electrophoresis, Western blot analysis, MALDI-TOF Mass spectrometry, and native-PAGE combined with activity staining of TAA. The results showed that TAA exists not only in germinated conidia but also in conidia. Some bands representing degraded products of TAA were detected. Conidia, which formed on starch (SCYA), glucose (DCYA), and glycerol (GCYA) plates, contained mature TAA. Only one active band of TAA was detected after native-PAGE activity staining. In addition, TAA activity was detected in cell extracts of conidia using 0.5 M acetate buffer, pH 5.2, as extraction buffer, but was not detected in whole conidia or cell debris. The results indicate that TAA exists in conidia in active form even when starch, glucose, or glycerol is used as carbon source. TAA might belong to a set of basal proteins inside conidia, which helps in imbibition and germination of conidia.  相似文献   

18.
The present work was carried out to determine the optimum culture conditions of Phanerochaete chrysosporium (ATCC 20696) for maximizing ligninolytic enzyme production. Additionally, separation of its lignin peroxidase was conducted. After experiments, an optimized culture medium/condition was constructed (per liter of Kirk’s medium): dextrose 10 g, ammonium tartrate 0.11 g, Tween-80 0.5 g, MnSO4 7 mg, and veratryl alcohol 0.3 g in 10 mM acetic acid buffer pH 4.5. Under the optimized experimental condition, both lignin peroxidase (LiP) and manganese peroxidase (MnP) were detected and reach the highest yield at 30°C on the 8th day culture. Salt precipitation methods was used in the extraction and purification processes. Results show that salt precipitation with 60% (NH4)2SO4 yielded the best result, especially toward LiP. Enzyme separation was conducted and two fractions with LiP activity. LiP1 and LiP2 were produced using three columns sequentially: desalting column, Q FF ion exchange column and Sepharyl S-300 HR gel filtration. LiP1 and LiP2 had been purified by 9.6- and 7.6-fold with a yield of 22.9% and 18.6%, respectively. According to the data of sodium dodecyl sulfate polyacrilamide gel electrophoresis (SDS-PAGE), the molecular weights of the enzymes are 38 kDa and 40 kDa, respectively.  相似文献   

19.
An intracellular glucoamylase (E.C. 3.2.1.3) was purified to homogeneity from Lactobacillus amylovorus on a Fast Protein Liquid Chromatography System (FPLC) with a Mono Q ion-exchanger and two Superose 12 gel filtration columns arranged in series. The enzyme activity was quantified with a specific, chromogenic substrate, p-nitrophenyl-β-maltoside. Preparative gel electrophoresis was then used to further purify active enzyme fractions. Native polyacrylamide gel electrophoresis (Native-PAGE) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of the purified enzyme showed a single protein band of molecular weight 47 kDa. Glucoamylase activity of the purified protein was confirmed by its ability to degrade starch on a 0.025% starch-polyacrylamide gel stained with I2/KI. Glucoamylase exhibited optimum catalytic activity at pH 6.0 and 45°C, and the enzyme had an isoelectric point near 4.39. The glucoamylase contained high levels of hydrophilic amino acids, comparable to fungal glucoamylases. Received: 12 July 1996 / Accepted: 10 September 1996  相似文献   

20.
The oligomeric form of the larger subunit designated as Am produced by alkali treatment of ribulose-1,5-diphosphate carboxylase from the purple sulfur bacterium, Chromatium strain D, retained partial enzymic activity in the absence of the small subunit (B). Supporting evidence was obtained by polyacrylamide gel electrophoresis at pH 8.9 and Sephadex G-200 gel filtration equilibrated with alkaline buffer at pH 9.2. The specific enzyme activity of Am (45 nmoles CO2 fixed/mg protein/min) was approximately 15% of the native intact enzyme molecule. By sodium dodecyl sulfatepolyacrylamide gel electrophoresis, the Am preparation was proved to be free from contamination of subunit B. With reservation of the sensitivity limit of this particular technique we concur that the larger subunit is the catalytic entity of the carboxylase reaction. The optimum pH of the ribulose-1,5-diphosphate carboxylase reaction catalyzed by isolated Am lies on the alkaline side at about pH 8.3 with or without Mg2+. The undissociated native enzyme possesses an optimum pH on the alkaline side in the absence of Mg2+, which shifts to the acidic side in the presence of Mg2+. From this behavior it is inferred that the association of the smaller subunit with the larger subunit causes conformational stabilization of the enzyme molecule with an accompanying change in the pH optimum due to Mg2+.  相似文献   

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