scholarly journals Purification and characterization of cytosolic and microsomal cyclophilins from maize (Zea mays)

1996 ◽  
Vol 315 (3) ◽  
pp. 965-970 ◽  
Author(s):  
Philip S. SHELDON ◽  
Michael A. VENIS

Methods for the purification and separation of peptidyl prolyl cis–trans isomerase (PPI) from cytosolic and microsomal fractions of etiolated maize are described. On SDS/PAGE, the purified preparations appear as single polypeptides with molecular masses of 17.5 kDa and 17.7 kDa respectively. Instead of using immobilized cyclosporin A derivatives as affinity adsorbents, our methods employ conventional techniques enabling purification of the proteins on a much larger scale than previously described. An antiserum raised against the cytosolic PPI recognizes polypeptides of similar molecular mass from a wide range of plant species on an immunoblot. There is virtually no recognition of the microsomal PPI. The cytosolic and microsomal PPIs are inhibited by cyclosporin A (Ki = 6 nM in both cases), indicating that they are cyclophilins. The cytosolic enzyme is inactivated by 5 mM N-ethylmaleimide and 2 mM phenylglyoxal. N-terminal sequencing of the microsomal PPI indicates a high level of sequence similarity with the N-terminal sequence of mature animal s-cyclophilin (cyclophilin B).

1997 ◽  
Vol 52 (11-12) ◽  
pp. 740-746 ◽  
Author(s):  
Röbbe Wünschiers ◽  
Thomas Zinn ◽  
Dietmar Linder ◽  
Rüdiger Schulz

Abstract Purification of a soluble cytochrome c6 from the unicellular green alga Scenedesmus obliquus by a simple and rapid method is described. The purification procedure includes ammonium sulfate precipitation and non-denaturating PAGE. The N-terminal sequence of the first 20 amino acids was determined and shows 85% similarity and 75% identity to the sequence of cytochrome c6 from the green alga Monoraphidium braunii. The ferrocyto-chrome shows typical UV/VIS absorption peaks at 552.9, 521.9 and 415.7 nm. The apparent molecular mass was estimated to be 12 kD a by SDS-PAGE. EPR-spectroscopy at 20K shows resonances indicative for two distinct low-spin heme forms.


2010 ◽  
Vol 65 (11-12) ◽  
pp. 726-732 ◽  
Author(s):  
Wei Wang ◽  
Bin Huang ◽  
Zhi-Guo Feng ◽  
Xiao-Ping Chen ◽  
Win-Xin Tang ◽  
...  

Daintain/AIF-1 was identified from injured rat carotid arteries and porcine intestine in the mid 1990s. It is involved in autoimmune disorders, chronic rejection of allografts, gliomas, and breast cancer. Since it is convenient and economical to obtain such a peptide biologically, in this study, we describe the expression, purification, and characterization of recombinant human daintain/AIF-1 (rhdaintain/AIF-1). The backbone of vector pET32a, a high-level expression plasmid, was used to construct the pET32a-daintain/AIF-1 plasmid for daintain/AIF-1 expression in Escherichia coli. The recombinant daintain/AIF-1 protein was solubly expressed in the BL21 (DE3) strain and was purifi ed by Ni2+ affinity chromatography. After purification, the recombinant protein showed the expected size of 18 kDa on Tricine-SDS-PAGE gels which was further confirmed by Western blotting. A total of 34.0 mg of high purity (over 98%) rhdaintain/AIF-1 was obtained from 1 L culture. The recombinant peptide was able to increase blood glucose elimination rates and enhance the proliferation of human MCF-7 cells. These results suggest that biological activity of the recombinant peptide was preserved after purification


1991 ◽  
Vol 279 (3) ◽  
pp. 775-779 ◽  
Author(s):  
B C Baker ◽  
C J Campbell ◽  
C J Grinham ◽  
G Turcatti

Rat factor D has been purified to homogeneity (10,559-fold) from serum by chromatography on CM-Sepharose Fast Flow, phenyl-Sepharose CL-4B and Mono S and has been shown to resemble its human and mouse counterparts both in substrate specificity and in its susceptibility to inhibition by the organophosphorous inhibitor di-isopropylfluorophosphate. The rat enzyme, however, is heavily glycosylated and binds to wheat-germ lectin-Sepharose 6MB and 5-hydroxytryptamine-agarose, but not to concanavalin A-Sepharose 4B. All of the carbohydrate chains are N-linked. Enzymic removal of this carbohydrate decreased the Mr by approx. 15,000. The deglycosylated rat enzyme had the same mobility as native human factor D on SDS/PAGE, corresponding to an Mr of 24,500. N-Terminal sequence analysis of the first 30 amino acids of rat factor D highlighted the sequence similarity with human factor D (greater than 76%) and, in particular, with mouse adipsin (greater than 93%).


2006 ◽  
Vol 52 (7) ◽  
pp. 651-657 ◽  
Author(s):  
Luis Morales de la Vega ◽  
J Eleazar Barboza-Corona ◽  
Maria G Aguilar-Uscanga ◽  
Mario Ramírez-Lepe

A chitinolytic enzyme from Bacillus thuringiensis subsp. aizawai has been purified and its molecular mass was estimated ca. 66 kDa by sodium dodecyl sulfate – polyacryamide gel electrophoresis (SDS–PAGE). The enzyme was able to hydrolyze chitin to chitobiosides but not carboxymethylcellulose, cellulose, pullulan, and laminarin. Optimal pH and temperature were detected at 6 and 50 °C, respectively. Stability, in the absence of substrate, was observed at temperatures less than 60 °C and pH between 5 and 8. Enzyme activity was significantly inhibited by K+ and EDTA and completely inhibited by Hg2+. Purified chitinase showed lytic activity against cell walls from six phytopathogenic fungi and inhibited the mycelial growth of both Fusarium sp. and Sclerotium rolfsii. The biocontrol efficacy of the enzyme was tested in the protection of bean seeds infested with six phytopathogenic fungi.Key words: chitinase, Bacillus thuringiensis, purification, phytopathogenic fungi.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Saleh A. Mohamed ◽  
Mohamed F. Elshal ◽  
Taha A. Kumosani ◽  
Alia M. Aldahlawi

L-asparaginase from bacteria has been used in treatment of acute lymphoblastic leukemia. The aim of this study was to purify and characterize L-asparaginase fromPhaseolus vulgarisseeds instead of microbial sources. L-asparaginase was purified to apparent homogeneity. The enzyme has molecular mass of 79 kDa. The purified asparaginase had very low activity toward a number of asparagine and glutamine analogues. L-asparaginase was free from glutaminase activity. Kinetic parameters, Km andVmax of purified enzyme, were found to be 6.72 mM and 0.16 μM, respectively. The enzyme had optimum pH at 8.0. The enzyme showed high stability at alkaline pH (pH 7.5–9.0) when incubated for up to 24 h. L-asparaginase had the same temperature optimum and thermal stability at 37°C. K+was able to greatly enhance the activity of asparaginase by 150% compared with other metals tested. In conclusion, L-asparaginase showed no glutaminase activity and good stability over a wide range of physiological conditions, and thus it could be used as a potential candidate for treatment of acute lymphoblastic leukemia.


1999 ◽  
Vol 276 (3) ◽  
pp. F398-F408 ◽  
Author(s):  
John C. Edwards

Several closely related proteins that have been implicated as chloride channels of intracellular membranes have recently been described. We report here the molecular cloning and characterization of a new member of this family from human cells. On the basis of sequence similarity, we conclude that this new protein represents the human version of a previously described protein from rat brain named p64H1. The human version of p64H1 (huH1) is a 28.7-kDa protein that shows an apparent molecular mass of 31 kDa by SDS-PAGE. A single 4.5-kb message is detected on Northern blots and is present in all tissues probed. The protein is expressed in an intracellular vesicular pattern in Panc-1 cells that is distinct from the endoplasmic reticulum, fluid-phase endocytic, and transferrin-recycling compartments, but which does colocalize with caveolin. In human kidney, huH1 is highly expressed in a diffuse pattern in the apical domain of proximal tubule cells. huH1 is expressed less abundantly in a vesicular pattern in glomeruli and distal nephron.


1996 ◽  
Vol 42 (6) ◽  
pp. 609-612 ◽  
Author(s):  
Bhagyashree Joshi ◽  
Jayant M. Khire ◽  
Hephzibah SivaRaman ◽  
M. Islam Khan

A lectin was isolated from culture filtrates of Xanthomonas campestris NCIM 5028, by a simple procedure of hydrophobic chromatography on phenyl-Sepharose after ammonium sulphate precipitation. The lectin was a heterodimer, with subunit molecular masses of 30 000 and 28 000. Gel filtration on S-300 column, calibrated with markers, showed its molecular mass to be approximately 70 000. Its isoelectric point was 7.2. The agglutination of the rabbit erythrocytes by the lectin was inhibited by fetuin glycopeptides and host plant (Brassica oleracea) extracts.Key words: Xanthomonas campestris, lectin, purification.


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