scholarly journals Streptomyces lavendulaeProtease Inhibitor: Purification, Gene Overexpression, and 3-Dimensional Structure

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
D. E. El-Hadedy ◽  
El-Sayed E. Mostafa ◽  
Moataza M. Saad

Protease inhibitorstrypsin (STI1, Streptomyces trypsin inhibitor 1) has been identified, purified by ammonium sulfate precipitation and Sephadex G-100 gel filtration. SDS-PAGE of protease inhibitor showed molecular weight of approximately 10 KDa. PCR product (~1615 bp) ofsti1gene was cloned in expression vectorpACYC177/ET3dand transformed inEscherichia coliJM109.Protease inhibitorstrypsin was purified and used as antivirus against Coxsackievirus B3 (CVB3). CVB3 is one of the major causative agents of chronic, subacute, acute, and fulminant myocarditis as well as pancreatitis and aseptic meningitis. It has been reported that more than 50% of human myocarditis is associated with CVB3 infection.

2021 ◽  
Vol 18 (15) ◽  
Author(s):  
Kranokpron MOOLWANG ◽  
Sakda DADUANG ◽  
Thidarat SOMDEE ◽  
Theerasak SOMDEE

MlrA is a gene involved in the degradation of toxic cyanobacterial microcystins. This gene encodes microcystinase, mlrA, the 1st enzyme in the pathway that breaks down toxic cyanobacterial microcystins. In this study, primers were designed, and polymerase chain reaction (PCR) was performed to amplify the mlrA gene in Novosphincgobium sp. KKU25s. A PCR product of 752 base pairs was obtained. The nucleotide sequence of the mlrA gene of Novosphingobium sp. KKU25s was similar to that of Sphingomonas sp. ACM-3962 (98 % similarity). The mlrA gene of Novosphingobium sp. KKU25s was further cloned into the pGEM T-Easy plasmid to obtain the nucleotide sequence of the mlrA gene. The gene was also ligated into the pET32a plasmid for gene expression. Expression was induced by isopropyl β-D-1-thiogalactopyranoside (IPTG) and verified using SDS-PAGE. The expressed protein was approximately 22 kilodaltons. The cell-free extract (CE) containing the crude protein from confirmed recombinant cells showed high activity in the biodegradation of [Dha7] MC-LR. [Dha7] MC-LR at an initial concentration of 30 mg L-1 and was completely biodegraded within 30 h. A distinct product derived from [Dha7] MC-LR appeared with a decrease in the [Dha7] MC-LR peak in the HPLC profile. The product (m/z 999.51) showed a molecular weight of 18, which is higher than that of native [Dha7] MC-LR (m/z 981.50), and was determined to be a linearized peptide fragment of [Dha7] MC-LR using LC-MS analysis. The 3-dimensional structure of microcystinase was predicted from the amino acid sequence deduced from the mlrA gene by the Swiss Model and Phyre2 programs. The structure contained a predicted alpha helix. The predicted 3-dimensional structure was also similar to that of a protein in the CAAX protease group. HIGHLIGHTS Research focused on characterization of microcystinase (MlrA) protein First research worked on the degradation of [Dha7] MC-LR by MlrA This work is useful for the applications aimed at the removal of MCs in freshwater environments GRAPHICAL ABSTRACT


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Imran Ali ◽  
Ali Akbar ◽  
Mohammad Anwar ◽  
Sehanat Prasongsuk ◽  
Pongtharin Lotrakul ◽  
...  

An extracellularα-amylase from the obligate halophilicAspergillus penicillioidesTISTR3639 strain was produced and enriched to apparent homogeneity by ammonium sulfate precipitation and Sephadex G100 gel filtration column chromatography. The mass of the purified amylase was estimated to be 42 kDa by SDS-PAGE. With soluble starch as the substrate it had a specific activity of 118.42 U·mg−1andVmax⁡andKmvalues of 1.05 µmol·min−1·mg−1and 5.41 mg·mL−1, respectively. The enzyme was found to have certain polyextremophilic characteristics, with an optimum activity at pH 9, 80°C, and 300 g·L−1NaCl. The addition of CaCl2at 2 mM was found to slightly enhance the amylase activity, while ZnCl2, FeCl2, or EDTA at 2 mM was strongly or moderately inhibitory, respectively, suggesting the requirement for a (non-Fe2+or Zn2+) divalent cation. The enzyme retained more than 80% of its activity when incubated with three different laundry detergents and had a better performance compared to a commercial amylase and three detergents in the presence of increasing NaCl concentrations up to 300 g·L−1. Accordingly, it has a good potential for use as anα-amylase in a low water activity (high salt concentration) and at high pH and temperatures.


Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2078
Author(s):  
Saira Hussain ◽  
Ata-ur Rehman ◽  
David J. Luckett ◽  
S.M. Saqlan Naqvi ◽  
Christopher L. Blanchard

Valorization of vegetable oil waste residues is gaining importance due to their high protein and polyphenol contents. Protease inhibitors (PIs), proteins from these abundantly available waste residues, have recently gained importance in treating chronic diseases. This research aimed to use canola meal of genetically diverse Brassica napus genotypes, BLN-3347 and Rivette, to identify PIs with diverse functionalities in therapeutic and pharmacological applications. The canola meal PI purification steps involved: native PAGE and trypsin inhibition activity, followed by ammonium sulfate fractionation, anion exchange, gel filtration, and reverse-phase chromatography. The purified PI preparations were characterized using SDS-PAGE, isoelectric focusing (IEF), and N terminal sequencing. SDS-PAGE analysis of PI preparations under native reducing and nonreducing conditions revealed three polymorphic PIs in each genotype. The corresponding IEF of the genotype BLN-3347, exhibited three acidic isoforms with isoelectric points (pI) of 4.6, 4.0, and 3.9, while Rivette possessed three isoforms, exhibiting two basic forms of pI 8.65 and 9.9, and one acidic of pI 6.55. Purified PI preparations from both the genotypes displayed dipeptidyl peptidase-IV (DPP-IV) and angiotensin-converting enzyme (ACE) inhibition activities; the BLN-3347 PI preparation exhibited a strong inhibitory effect with lower IC50 values (DPP-IV 37.42 µg/mL; ACE 129 µg/mL) than that from Rivette (DPP-IV 67.97 µg/mL; ACE 376.2 µg/mL). In addition to potential human therapy, these highly polymorphic PIs, which can inhibit damaging serine proteases secreted by canola plant pathogens, have the potential to be used by canola plant breeders to seek qualitative trait locus (QTLs) linked to genes conferring resistance to canola diseases.


2008 ◽  
Vol 3 (3) ◽  
pp. 1934578X0800300
Author(s):  
Cortés-Vázquez Ma. Isabel ◽  
Muñoz-Sánchez José Luis ◽  
Briones-Martínez Roberto

A cationic peptidase, named hemisphaericin-C, has been purified from the juice of Bromelia hemisphaerica fruits by ammonium sulfate precipitation, gel filtration on Sephadex G-75 and cationic exchange chromatography on carboxymethyl cellulose (CMC), to yield a single 24 kDa band on SDS-polyacrylamide gel electrophoresis (SDS-PAGE), which showed esterase and proteolytic activities. The esterase activity was inhibited by E-64, leupeptin, and cystatin, but not by EDTA. Characterization of the primary specificity of hemisphaericin-C showed activity towards substrates specific for chymotrypsin: N-succinyl-L-Phe- p-nitroanilide (PHE pNA) and N-benzoyl-L-Tyr- p-nitroanilide (TYR pNA), and those for trypsin: N-benzoyl-L-arg- p-nitroanilide (BA pNA) to a lower degree. The higher selectivity, assessed by Vmax/Km, was obtained for PHE pNA, the substrate containing the aromatic lateral chain amino acid at the P1 position. The preference of hemisphaericin-C for PHE pNA gives a clue in the search for a chymotrypsin-like peptidase from a vegetal source.


Author(s):  
Robert Glaeser ◽  
Thomas Bauer ◽  
David Grano

In transmission electron microscopy, the 3-dimensional structure of an object is usually obtained in one of two ways. For objects which can be included in one specimen, as for example with elements included in freeze- dried whole mounts and examined with a high voltage microscope, stereo pairs can be obtained which exhibit the 3-D structure of the element. For objects which can not be included in one specimen, the 3-D shape is obtained by reconstruction from serial sections. However, without stereo imagery, only detail which remains constant within the thickness of the section can be used in the reconstruction; consequently, the choice is between a low resolution reconstruction using a few thick sections and a better resolution reconstruction using many thin sections, generally a tedious chore. This paper describes an approach to 3-D reconstruction which uses stereo images of serial thick sections to reconstruct an object including detail which changes within the depth of an individual thick section.


Author(s):  
A. Engel ◽  
A. Holzenburg ◽  
K. Stauffer ◽  
J. Rosenbusch ◽  
U. Aebi

Reconstitution of solubilized and purified membrane proteins in the presence of phospholipids into vesicles allows their functions to be studied by simple bulk measurements (e.g. diffusion of differently sized solutes) or by conductance measurements after transformation into planar membranes. On the other hand, reconstitution into regular protein-lipid arrays, usually forming at a specific lipid-to-protein ratio, provides the basis for determining the 3-dimensional structure of membrane proteins employing the tools of electron crystallography.To refine reconstitution conditions for reproducibly inducing formation of large and highly ordered protein-lipid membranes that are suitable for both electron crystallography and patch clamping experiments aimed at their functional characterization, we built a flow-dialysis device that allows precise control of temperature and flow-rate (Fig. 1). The flow rate is generated by a peristaltic pump and can be adjusted from 1 to 500 ml/h. The dialysis buffer is brought to a preselected temperature during its travel through a meandering path before it enters the dialysis reservoir. A Z-80 based computer controls a Peltier element allowing the temperature profile to be programmed as function of time.


Author(s):  
D.P. Bazett-Jones ◽  
F.P. Ottensmeyer

It has been shown for some time that it is possible to obtain images of small unstained proteins, with a resolution of approximately 5Å using dark field electron microscopy (1,2). Applying this technique, we have observed a uniformity in size and shape of the 2-dimensional images of pure specimens of fish protamines (salmon, herring (clupeine, Y-l) and rainbow trout (Salmo irideus)). On the basis of these images, a model for the 3-dimensional structure of the fish protamines has been proposed (2).The known amino acid sequences of fish protamines show stretches of positively charged arginines, separated by regions of neutral amino acids (3). The proposed model for protamine structure (2) consists of an irregular, right-handed helix with the segments of adjacent arginines forming the loops of the coil.


Author(s):  
J. Jakana ◽  
M.F. Schmid ◽  
P. Matsudaira ◽  
W. Chiu

Actin is a protein found in all eukaryotic cells. In its polymerized form, the cells use it for motility, cytokinesis and for cytoskeletal support. An example of this latter class is the actin bundle in the acrosomal process from the Limulus sperm. The different functions actin performs seem to arise from its interaction with the actin binding proteins. A 3-dimensional structure of this macromolecular assembly is essential to provide a structural basis for understanding this interaction in relationship to its development and functions.


1997 ◽  
Vol 325 (3) ◽  
pp. 761-769 ◽  
Author(s):  
Isabelle GARCIA ◽  
Matthew RODGERS ◽  
Catherine LENNE ◽  
Anne ROLLAND ◽  
Alain SAILLAND ◽  
...  

p-Hydroxyphenylpyruvate dioxygenase catalyses the transformation of p-hydroxyphenylpyruvate into homogentisate. In plants this enzyme has a crucial role because homogentisate is the aromatic precursor of all prenylquinones. Furthermore this enzyme was recently identified as the molecular target for new families of potent herbicides. In this study we examine precisely the localization of p-hydroxyphenylpyruvate dioxygenase activity within carrot cells. Our results provide evidence that, in cultured carrot cells, p-hydroxyphenylpyruvate dioxygenase is associated with the cytosol. Purification and SDS/PAGE analysis of this enzyme revealed that its activity is associated with a polypeptide of 45–46 kDa. This protein specifically cross-reacts with an antiserum raised against the p-hydroxyphenylpyruvate dioxygenase of Pseudomonas fluorescens. Gel-filtration chromatography indicates that the enzyme behaves as a homodimer. We also report the isolation and nucleotide sequence of a cDNA encoding a carrot p-hydroxyphenylpyruvate dioxygenase. The nucleotide sequence (1684 bp) encodes a protein of 442 amino acid residues with a molecular mass of 48094 Da and shows specific C-terminal regions of similarity with other p-hydroxyphenylpyruvate dioxygenases. This cDNA encodes a functional p-hydroxyphenylpyruvate dioxygenase, as evidenced by expression studies with transformed Escherichia coli cells. Comparison of the N-terminal sequence of the 45–46 kDa polypeptide purified from carrot cells with the deduced peptide sequence of the cDNA confirms that this polypeptide supports p-hydroxyphenylpyruvate dioxygenase activity. Immunodetection studies of the native enzyme in carrot cellular extracts reveal that N-terminal proteolysis occurs during the process of purification. This proteolysis explains the difference in molecular masses between the purified protein and the deduced polypeptide.


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