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1.
We used gel filtration chromatography, anion-exchange chromatography and polyacrylamide gel electrophoresis to purify tributyltin-binding protein type 2 (TBT-bp 2) from plasma of Japanese flounder (Paralichthys olivaceus) injected intraperitoneally with TBT (5.0 mg/kg body weight). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that the molecular mass of TBT-bp 2 was approximately 48 kDa, and isoelectric focusing-polyacrylamide gel electrophoresis indicated that the isoelectric point was approximately 3.0. TBT-bp 2 contained 40% N-glycan. The complete cDNA nucleotide sequence and the genome sequence of TBT-bp 2 were determined by means of rapid amplification of cDNA ends of liver tissue of Japanese flounder and a genome-walking technique, respectively. The 216 amino acid sequence of TBT-bp 2 showed 47% identity to the sequences of puffer fish (Takifugu pardalis) saxitoxin- and tetrodotoxin-binding protein but only 27% similarity to the sequence of TBT-bp 1. Analysis of the motif sequence of the amino acid sequence and the structure of the gene encoding TBT-bp 2 suggested that this protein belongs to the lipocalin superfamily.  相似文献   

2.
In human placenta 85% of total hexokinase activity (EC 2.7.1.1) was found in a soluble form. Of this, 70% is hexokinase type I while the remaining 30% is hexokinase type II. All the bound hexokinase is type I. Soluble hexokinase I was purified 11,000-fold by a combination of ion-exchange chromatography, affinity chromatography, and dye-ligand chromatography. The specific activity was 190 units/mg protein with a 75% yield. The enzyme shows only one band in nondenaturing polyacrylamide gel electrophoresis that stains for protein and enzymatic activity; however, two components (with Mr 112,000 and 103,000) were constantly seen in sodium dodecyl sulfate-gel electrophoresis. Many attempts were made to separate these two proteins under native conditions; however, only one peak of activity was obtained when the enzyme was submitted to gel filtration (Mr 118,000), preparative isoelectric focusing (pI 5.9), anion-exchange chromatography, hydroxylapatite chromatography, and affinity chromatography on immobilized dyes and immobilized glucosamine. The high and low molecular weight hexokinases show the same isoelectric point under denaturing conditions as determined by two-dimensional gel electrophoresis. Each hexokinase subtype was obtained by preparative sodium dodecyl sulfate electrophoresis followed by electroelution. Monospecific antibodies raised in rabbits against electroeluted high and low molecular weight hexokinases were not able to recognize the native enzymes but each of them detected both hexokinases on immunoblots. Amino acid compositions and peptide mapping by limited proteolysis of the high and low molecular weight hexokinases were also performed and suggested a strong homology between these two subtypes of human hexokinase I.  相似文献   

3.
Summary A soluble trehalase was purified more than 200-fold from the male accessory gland of the American cockroach,Periplaneta americana, by CM-cellulose, hydrophobic chromatography, and Sephacryl S-200 gel filtration. The final preparation was homogeneous as judged by polyacryl-amide gel electrophoresis in the absence and presence of SDS, isoelectric focusing, and immuno-diffusion tests. The purified enzyme was maximally active at pH 5.2, and showed high specificity for trehalose with aK m of 0.98 mM. The isoelectric point was 4.7. The molecular weight of the enzyme (75,000) was determined by molecular sieve chromatography and SDS-polyacrylamide gel electrophoresis. The amino acid composition was determined and compared with those of trehalases purified from other sources. The trehalase could be stained for carbohydrate with the periodic acid-Schiff's reagent following SDS-polyacrylamide gel electrophoresis, indicating that it was a glycoprotein. Another soluble trehalase and two types of fat body trehalases could be highly purified by the method described. A comparison of the properties of trehalases from the accessory gland and the fat body showed some resemblance.  相似文献   

4.
An exo-1,4-beta-glucanase from culture solution of the rot fungus Sporotrichum pulverulentum (formerly called Chrysosporium lignorum) grown on powder cellulose as the sole carbon source has been extensively purified and characterized with respect to some physico-chemical properties. The purification has been carried out in a five-step procedure comprising chromatography on DEAE-Sephadex, gel filtration on polyacrylamide P-150, activation on a Dowex 2-X8 anion exchanger, chromatography on Concanavalin A-Sepharose and chromatography on SP-Sephadex. The purified enzyme was found to be pure and homogeneous by analytical polyacrylamide electrophoresis, by electrophoresis on dodecylsulphate gels and by analytical polyacrylamide electrophoresis, by electrophoresis on dodecylsulphate gels and by analytical isoelectric focusing. A single symmetrical peak was obtained with the free zone electrophoresis method. The purification factor is about 15 and the yield of exo-1,4-beta-glucanase activity 7%. After purification, the enzyme showed no viscosity-decreasing activity towards carboxymethyl-cellulose solutions. The exo-1,4-beta-glucanase was isoelectric at pH 4.3 (4 degrees C). A molecular weight of 48600 was calculated on the basis of a knowledge of the partial specific volume, ultracentrifugation data and the amino acid composition. The enzyme contained no carbohydrate.  相似文献   

5.
Phosphodiesterase from the venom of Crotalus ruber ruber   总被引:1,自引:0,他引:1  
Phosphodiesterase was isolated from the venom of Crotalus ruber ruber from the U.S.A. using the gel filtration on a Sephadex G-75 column, followed by anion or cation exchange chromatography. Phosphodiesterase was homogeneous as established by a single band on acrylamide gel electrophoresis and isoelectric focusing electrophoresis. Phosphodiesterase activity was inhibited by ethylenediamine tetraacetic acid (EDTA), o-phenanthroline, thioglycolic acid or p-chloromercuribenzoate (PCMB), but not by soybean trypsin inhibitor (SBTI) or benzamidine. The molecular weight of this enzyme was determined to be approx. 98,000 and the isoelectric point was found to be pH 10.5 by isoelectric focusing with carrier ampholyte. This enzyme contained 1.04 mol zinc per mol. The Michaelis constant (Km) of this enzyme for p-nitrophenyl thymidine-5'-phosphate and inhibition constant (Ki) for PCMB were found to be 8.3 X 10(-3) and 1.2 X 10(-2) M, respectively.  相似文献   

6.
Nontoxic abrus lectin has been prepared by a new purification procedure. The method is accomplished by 45% saturation ammonium sulfate fractionation from a 5% acetic acid extract of the seeds of Abrus precatorius followed by diethylaminoethyl-Sephadex A-50 and Sepharose 4B affinity chromatography. The abrus lectin appeared homogeneous as judged by electrophoresis, analytical ultracentrifugation, and isoelectric focusing. The lectin molecule has a weight of 126,000 as determined by sedimentation equilibrium. It is composed of four subunits, of which two pairs have either identical or closely similar molecular sizes (33,800 and 32,200 daltons) as revealed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The results of amino acid analyses are given; none of the cysteic acid appears to arise from cysteine. An electrofocusing experiment indicated the isoelectric point to be 5.0. Crystals large enough for x-ray investigation were obtained by a vapor diffusion technique. X-ray precession photographs revealed that abrus lectin crystallizes in a tetragonal unit cell of symmetry P41212 and dimensions a = 140 and c = 210 A. The asymmetric unit contains 2 protein molecules of molecular weight 126,000 and has a solvent content of approximately 41% by volume.  相似文献   

7.
An organic solvent soluble polypeptide has been isolated from photoreceptor complexes and chromatophores of Rhodospirillum rubrum. After extraction of the protein from lyophilized samples with 1:1 chloroform-methanol, it was purified by column chromatography. Its isoelectric point determined by isoelectric focusing was 7.10. When analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the purified polypeptide ran as a single band of an apparent molecular weight of 12 000. However, according to amino acid analysis, the minimal molecular weight based on one histidine residue per polypeptide is 19 000. The polypeptide contains no cysteine and no tyrosine. Amino acid analysis indicated that three methionines were present per histidine residue and cyanogen bromide cleavage gave four smaller peptides which were isolated by two-dimensional electrophoresis and chromatography. Spectroscopic analysis indicated the presence of three tryptophan residues per histidine and N-bromosuccinamide cleavage also gave four smaller peptides which could be isolated by two-dimensional electrophoresis and chromatography. The C-terminal amino acid was shown to be glycine by two methods, while the N-terminal amino acid appears to be blocked. The organic solvent soluble polypeptide accounts for approximately 50% of the chromatophore protein and seems to bind the antenna bacteriochlorophyll and carotenoid molecules. Using this procedure, organic solvent soluble polypeptides were isolated from several photosynthetic bacteria and were found to have substantially different amino acid contents.  相似文献   

8.
The high-mobility-group (HMG) non-histone chromosomal proteins from calf thymus, liver, spleen and kidney were extracted, and fractionated by CM-Sephadex chromatography and trichloroacetic acid precipitation. The isolated proteins HMG 1, HMG 2 and HMG 17 from the tissues were compared by polyacrylamide-gel electrophoresis, isoelectric focusing and amino acid analysis. The results show that the three proteins are very similar in the tissues studied, implying a lack of tissue specificity.  相似文献   

9.
H C Chang  M S Bergdoll 《Biochemistry》1979,18(10):1937-1942
A method was developed for the isolation of staphylococcal enterotoxin D in highly purified form from cultures of Staphylococcus aureus strain 1151m. The method involves removal of the toxin from the culture supernatant fluid with the ion-exchange resin CG-50 followed by chromatography on carboxymethylcellulose (twice) and by gel filtration on Sephadex G-75 (twice). The purified toxin is homogeneous by polyacrylamide gel and sodium dodecyl sulfate-polyacrylamide gel electrophoresis and double gel diffusion tests. It is a simple, colorless, antigenic protein with an isoelectric point of 7.4 as determined by isoelectric focusing. Its molecular weight was determined to be 27 300 +/- 700 by molecular sieve chromatography on Sephadex G-100 and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Its serological activity is stable over a wide range of pH values (1.2--10.7). The enterotoxin consists of 236 amino acid residues and contains no free sulfhydryl groups. End-group analysis showed serine to be the NH2-terminal amino acid and lysine to be the COOH-terminal amino acid.  相似文献   

10.
An anti-epilepsy peptide (AEP) was isolated and purified from venom of the scorpion Buthus martensii Karsch. The purification procedure included CM-Sephadex C-50 chromatography, gel filtration on Sephadex G-50 and DEAE-Sephadex A-50 chromatography. Its homogeneity was demonstrated by pH 4.3 polyacrylamide-disc-gel electrophoresis, focusing electrophoresis and SDS/polyacrylamide-disc-gel electrophoresis. The Mr of this peptide, calculated from measurements in SDS/15%-polyacrylamide-disc-gel and SDS/20%-polyacrylamide-disc-gel electrophoresis, is 8300. The isoelectric point is 8.52 by pH 8-9.5-range isoelectric focusing. No haemorrhagic or toxic activities were found. No toxicity was found even after the dose reached 28 mg/kg. The pharmacological tests showed that the AEP had no effect on heart rate, blood pressure or electrocardiogram, but strongly inhibited epilepsy induced by coriaria lactone and cephaloridine. The fluorescence spectrum showed that the peptide has a strong emission peak at 337 nm. Amino acid analysis suggested that the AEP is composed of 66 residues from 18 amino acids and has an Mr of 8290. The sequence of the first 50 N-terminal residues is as follows: Asp-Gly-Tyr-Ile-Arg-Gly-Ser-Asp-Asn-Cys-Lys-Val-Ser-Cys-Leu-Leu-Gly-Asn- Glu-Gly - Cys-Asn-Lys-Glu-Cys-Arg-Ala-Tyr-Gly-Ala-Ser-Tyr-Gly-Tyr-Cys-Trp-Thr-Val- Lys-Leu - Ala-Gln-Asp-Cys-Glu-Gly-Leu-Pro-Asp-Thr-.  相似文献   

11.
Acid trehalase was purified from the yeast suc2 deletion mutant. After hydrophobic interaction chromatography, the enzyme could be purified to a single band or peak by a further step of either polyacrylamide gel electrophoresis, gel filtration, or isoelectric focusing. An apparent molecular mass of 218,000 Da was calculated from gel filtration. Polyacrylamide gel electrophoresis of the purified enzyme in the presence of sodium dodecyl sulfate suggested a molecular mass of 216,000 Da. Endoglycosidase H digestion of the purified enzyme resulted after sodium dodecyl sulfate gel electrophoresis in one distinct band at 41,000 Da, representing the mannose-free protein moiety of acid trehalase. The carbohydrate content of the enzyme was 86%. Amino acid analysis indicated 354 residues/molecule of enzyme including 9 cysteine moieties and only 1 methionine. The isoelectric point of the enzyme was estimated by gel electrofocusing to be approximately 4.7. The catalytic activity showed a maximum at pH 4.5. The activity of the enzyme was not inhibited by 10 mM each of HgCl2, EDTA, iodoacetic acid, phenanthrolinium chloride or phenylmethylsulfonyl fluoride. There was no activation by divalent metal ions. The acid trehalase exhibited an apparent Km for trehalose of 4.7 +/- 0.1 mM and a Vmax of 99 mumol of trehalose min-1 X mg-1 at 37 degrees C and pH 4.5. The acid trehalase is located in the vacuoles. The rabbit antiserum raised against acid trehalase exhibited strong cross-reaction with purified invertase. These cross-reactions were removed by affinity chromatography using invertase coupled to CNBr-activated Sepharose 4B. Precipitation of acid trehalase activity was observed with the purified antiserum.  相似文献   

12.
用分子筛和快速蛋白质液相色谱从烙铁头(TRrimeresurus mucrosquamatus)蛇毒中分离了一个新的碱性肌肉毒素,命名为TMPB。它的分子量为16000,等电点为9.2.用蛋白质序列仪测定了其N端24个氨基酸残基,TMPB与其他两个从同种蛇毒中分离到的碱性磷酯酶A2的同源性分别为41.7%和54.2%《  相似文献   

13.
Human neutrophil elastase from normal donors has been purified using an isolation procedure which included sequential sodium chloride extraction, Aprotinin-Sepharose affinity chromatography, CM-cellulose ion-exchange chromatography, and AcA44 gel filtration chromatography. The inclusion of this last purification step was crucial for separating inactive lower molecular weight species from the active forms of neutrophil elastase and resulted in a higher specific activity of the final preparation. Sodium dodecyl sulfate-polyacrylamide gradient gel electrophoresis of the reduced purified protein demonstrated three polypeptides of Mr 31,000, 28,000, and 27,500. Four polypeptides were resolved on acid gel electrophoresis; each of the four possessed amidolytic activity. Furthermore, peptide analysis of Staphylococcus aureus V8 protease digests indicated that these polypeptides are structurally related to each other and represent microheterogeneity of the purified protein. The apparent isoelectric points of these four forms as determined by two-dimensional electrophoresis range from 6.1 to 6.7. By utilizing microsequencing techniques, the first 40 residues of neutrophil elastase have been determined and compared with the reported sequence of elastase isolated from leukemic myeloid cells. In addition, a high degree of homology was found within the amino-terminal regions of neutrophil elastase and the serine proteinases porcine elastase, bovine chymotrypsin, human factor D, and the beta chain of plasmin.  相似文献   

14.
 本文采用离子交换层析,DNA亲和层析和硫酸铵盐析三步从人血清中分离纯化了一种肿瘤相关DNA结合蛋白质(64DP)。本方法较简便,产率提高。经SDS聚丙烯酰胺凝胶电泳和免疫电泳鉴定纯度符合要求。SDS聚丙烯酰胺凝胶电泳测定分子量为64,000。等电聚焦电泳测得等电点在4.2左右。醋酸纤维膜电泳和转移电泳表明其为一种α_1球蛋白。过碘酸西夫氏糖蛋白染色呈阳性反应。氨基酸分析和酶抑制试验证实64DP与α_1抗縻蛋白酶很相似。  相似文献   

15.
The 42,000 major outer membrane protein of Chromatium vinosum was purified by a combination on ion-exchange chromatography, gel filtration, and isoelectric focusing. Upon isoelectric focusing, the final material produced four major hands. Three of the four bands were isolated and analyzed for similarity or differences. Protease peptide maps and cyanogen bromide maps of the three isoelectric species were identical. When the isolated isoelectric species were refocused, each produced multiple isoelectric species, suggesting that the procedure used was generating the multiple charged species. Protease treatment of the isolated outer membrane produced a 31,000 fragment from the 42,000 protein. This fragment was isolated by preparative sodium sulfate-polyacrylamide gel electrophoresis. Although the amino acid compositions of the 42,000 protein and its 31,000 trypsin fragment were different, their polarity index was the same (45%). The amino-terminal sequences of the 42,000 protein and 31,000 trypsin fragment were identical, and it concluded that the amino-terminal was buried in the membrane.  相似文献   

16.
This paper presents a multidimensional profile of the human serum proteome, produced by a two-dimensional protein fractionation system based on liquid chromatography followed by characterization with capillary electrophoresis (CE). The first-dimension separation was done by chromatofocusing over a pH range from 8.5 to 4.0, where proteins were separated by their isoelectric points (pI). In this dimension, fractions were collected based on pH. The first-dimension pI fractions were then resolved in the second dimension by high-resolution, reversed-phase chromatography with a gradient of trifluoroacetic acid (TFA) in acetonitrile and TFA in water. A selected protein fraction collected from the second dimension by time was characterized by CE for molecular-weight estimation and for presence of isoforms. Molecular-weight estimation was done by sodium dodecyl sulfate capillary gel electrophoresis, where proteins were separated in the range of 10,000-225,000 Da. Detection of isoforms was done by capillary isoelectric focusing over a pH range of 3-10. A selected second-dimension fraction that contained the putative serum iron-binding protein transferrin was analyzed by these two CE techniques for molecular-weight determination and the presence of isoforms. The combination of two-dimensional protein fractionation and CE characterization represents an advanced tool for proteomics.  相似文献   

17.
A rat hepatoma cell line, FF101, established in serum-free, protein-free medium, synthesizes a growth factor(FF-GF). FF-GF was purified by gel filtration chromatography, cation-exchange chromatography and isoelectric focusing. Purified FF-GF was revealed as a single band on SDS-gel electrophoresis and its molecular weight was estimated to be 70 KDa. FF-GF stimulated DNA synthesis of various cells from different origins. The growth-promoting activities of FF-GF were abolished by treating with protease, dithiothreitol, acid and heating, whereas its activity was not inhibited by antibodies against acidic and basic fibroblast growth factors. These results indicate that FF-GF is a novel growth factor.  相似文献   

18.
The chemical synthesis of thymosin beta 4 using a solid-phase procedure has been accomplished. The synthetic product was found to be homogeneous on paper electrophoresis at pH 6.5, high-performance liquid chromatography on a reversed-phase column, and isoelectric focusing using polyacrylamide gels. The synthetic material was also shown to be identical with the natural thymosin beta 4 by tryptic peptide mapping, amino acid compositional analyses, and polyacrylamide gel isoelectric focusing. Biologically, synthetic thymosin beta 4 was found to be as active as the natural compound in a terminal deoxynucleotidyltransferase induction assay and in a macrophage migration inhibition assay. The proposed structure of the peptide hormone was thus confirmed by a chemical synthesis.  相似文献   

19.
Bacterially synthesized, recombinant-DNA-derived bovine growth hormone (r-bGH), prepared as described in the preceding paper in this journal, has been characterized in comparison with pituitary bovine growth hormone (pit-bGH). The characterization criteria include sodium dodecyl sulfate/polyacrylamide gel electrophoresis, automated N-terminal sequence analysis, amino acid composition, isoelectric focusing, reverse-phase high-performance liquid chromatography, ultraviolet absorbance, analysis for free protein thiol, sizing by gel filtration, circular dichroism, radioimmunoassay and biological activity in the hypophysectomized rat weight-gain assay. In every respect the r-bGH appears to be virtually identical to pit-bGH.  相似文献   

20.
Ribonuclease F1, the guanine-specific ribonuclease of Fusarium moniliforme, was purified to homogeneity by a combination of ethanol fractionation, affinity chromatography and DEAE-cellulose column chromatography. The adsorbent for the affinity chromatography was synthesized by the coupling of periodate-oxidized guanosine 5'-monophosphate to aminohexyl agarose followed by sodium borohydride reduction. Ribonuclease F2, the minor component, was also purified to near homogeneity by the same procedure. Ribonucleases F1 and F2 had the same molecular weight (about 11,000) as determined by gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. They also showed the same amino acid composition and differed only in the isoelectric point: 4.10 for F1 and 3.96 for F2.  相似文献   

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