scholarly journals Characterization of non-covalent oligomers of proteins treated with hypochlorous acid

2003 ◽  
Vol 375 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Anna L. P. CHAPMAN ◽  
Christine C. WINTERBOURN ◽  
Stephen O. BRENNAN ◽  
T. William JORDAN ◽  
Anthony J. KETTLE
Keyword(s):  
Hypochlorous Acid ◽  
Tissue Injury ◽  
Convincing Evidence ◽  
Protein Carbonyls ◽  
Molar Ratio ◽  
Myeloperoxidase Activity ◽  
Reducing Conditions ◽  
Sds Page ◽  
Methionine Residues

Hypochlorous acid (HOCl) is a potent oxidant produced by myeloperoxidase that causes aggregation of many proteins. Treatment of apohaemoglobin and apomyoglobin with HOCl produced a regular series of oligomer bands when the proteins were separated by SDS/PAGE under reducing conditions. Aggregation was detectable at a HOCl/protein molar ratio of 0.5:1 and was maximal at ratios of 10:1–20:1. Dimers formed within 1 min of adding HOCl, and further aggregation occurred over the next 30 min. No convincing evidence for covalent cross-linking was obtained by amino acid analysis, peptide analysis or electrospray ionization-MS of HOCl-modified apomyoglobin. The latter showed an increase in mass consistent with conversion of the two methionine residues into sulphoxides. A 5-fold excess of HOCl generated approximately three chloramines on the apomyoglobin. These underwent slow decay. Protein carbonyls were formed and were almost entirely located only on the polymer bands. Conversion of positively into negatively charged groups on the protein by succinylation caused preformed aggregates to dissociate. Treatment of apomyoglobin with taurine chloramine generated methionine sulphoxides but few protein carbonyls, and did not result in aggregation. We conclude that aggregation was due to strong, non-covalent interactions between protein chains. We propose that formation of protein carbonyls and possibly chloramines, along with methionine oxidation, alters protein folding to expose hydrophobic areas on neighbouring molecules that associate to form dimers and higher-molecular-mass aggregates. This process could lead to the formation of aggregated proteins at sites of myeloperoxidase activity and contribute to inflammatory tissue injury.

scholarly journals Purification, Characterization of an Entomopathogenic Fungal Lectin from Purpureocillium Lilacinum, and its Involvement in Pathogenesis Leading to Mycotic Keratitis

2021 ◽  
Author(s):  
Narasimhappagari Jagadeesh ◽  
Supreeth Kulkarni ◽  
Vishwanath B Chachadi ◽  
Sanhita Roy ◽  
Shashikala Inamdar
Keyword(s):  
Proinflammatory Response ◽  
Corneal Epithelial ◽  
Purpureocillium Lilacinum ◽  
Ammonium Sulphate Precipitation ◽  
Reducing Conditions ◽  
Sds Page ◽  
Fungal Lectin ◽  
Human Corneal Epithelial Cells ◽  
Ph Range

Abstract A lectin PCL, from Purpureocillium lilacinum a saprophytic, filamentous fungus was purified from the crude extract of the mycelia using 70% ammonium sulphate precipitation followed by affinity chromatography on mucin-Sepharose 4 B column. PCL is a monomer with an apparent molecular mass of 18.5 kDa as revealed by SDS-PAGE under both reducing and non reducing conditions. PCL is a blood group non specific lectin and has highest affinity towards Chitin, Mucin, asialo mucin, Fetuin with a MIC of 0.15µg/mL and also recognizes L-fucose, galactose, lactose, N-acetly galactosamine, Hyaluronic acid. PCL is stable up to 60 ºC and within the pH range 4–8. To understand its role in pathogenesis, effect of PCL was evaluated on Human Corneal Epithelial Cells (HCECs). PCL showed strong glycan mediated binding to HCECsand PCL showed proinflammatory response at lower concentrations by stimulating secretion of IL-6, 8. In contrast PCL at higher concentrations revealed opposite effect of HCECs growth inhibition. All these results collectively support the involvement of PCL in mediating host pathogen interactions possibly leading to pathogenesis. In addition, considering the entomopathogenic effect of Purpureocillium lilacinum, PCL may be attributed for this beneficiary effect, which needs to be explored.

scholarly journals Characterization of the 70 kDa polypeptide of the Na/Ca exchanger

1999 ◽  
Vol 338 (1) ◽  
pp. 139-145 ◽  
Author(s):  
Rami I. SABA ◽  
Alex BOLLEN ◽  
André HERCHUELZ
Keyword(s):  
Wild Type ◽  
Terminal Portion ◽  
Terminal Sequence ◽  
Protein Ratio ◽  
Reducing Conditions ◽  
Sds Page ◽  
Cloned Bovine ◽  
Sarcolemmal Vesicles ◽  
Exchange Activity

The Na/Ca exchanger is associated with 160, 120 and 70 kDa polypeptides whose nature is poorly understood. We have purified and characterized the Na/Ca exchanger from bovine cardiac sarcolemmal vesicles (SLVs) by using ion-exchange and affinity chromatographies. The Na/Ca exchanger-enriched fraction was reconstituted into asolectin liposomes [lipid to protein ratio 10:1 (w/w)] that showed Na/Ca exchange activity. Under non-reducing conditions, SDS/PAGE showed a single 70 kDa polypeptide, which was further characterized by immunoblots with different antibodies: SWant, raised against the purified exchanger protein; NH2-terminus, residues 1–21; NCX1, residues 393–406; and Exon F, residues 622–644. Immunoblots under reducing conditions with SWant, NH2-terminus and NCX1 showed three bands migrating at 160, 120 and 70 kDa for SLV preparations, whereas Exon F reacted only with the 160 and 120 kDa bands. Under non-reducing conditions, immunoblots with purified reconstituted Na/Ca exchanger showed a single band at 70 kDa reacting with SWant, NH2-terminus and NCX1 but not with Exon F. We conclude that the 70 kDa protein is associated with Na/Ca exchange activity, has the same N-terminal sequence as the cloned bovine cardiac exchanger, and has its length decreased by at least 35% from its C-terminal portion as compared with that of the wild-type exchanger.

scholarly journals PURIFICATION AND BIOCHEMICAL CHARACTERIZATION OF A T/TN SPECIFIC LECTIN FROM LEPECHINIA BULLATA SEEDS (LAMIACEAE)

2017 ◽  
Vol 9 (10) ◽  
pp. 165
Author(s):  
Wilches Torres A. ◽  
Rojas Caraballo J. ◽  
Sanabria E. ◽  
Reyes MontaÑo E ◽  
FernÁndez Alonso Jl ◽  
...  
Keyword(s):  
Isoelectric Focusing ◽  
Biochemical Characterization ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Reducing Conditions ◽  
Sds Page ◽  
Unique Band

Objective: This study focused on purifying and characterizing a lectin from Lepechinia bullata (L. bullata) seeds, and determining its specificity towards tumour-associated carbohydrate-antigens.Methods: Pigments were removed by washing the seeds with NH4OH 0.1 M pH 9.4 and treating the crude extracts with Pectinex®. The purification procedure consisted of anion exchange chromatography on diethylaminoethyl (DEAE)-Sephadex followed by affinity chromatography. For the characterization, the phase was used polyacrylamide gel electrophoresis-sodium dodecyl sulphate (SDS-PAGE), isoelectric focusing, hemagglutination assays, enzyme-linked lectinosorbent assay (ELLA) and thermal shift assay (TSA).Results: 6.2 mg of lectin were obtained from 100 g of seeds. It was able to agglutinate enzymatically treated erythrocytes with a minimal required lectin concentration of 7 μg. ml-1. Strong binding to asialo bovine submaxillary mucine (aBSM) was determined, corroborating Tn recognition.The isoelectric focusing showed a unique band at pH 8.5. Lectin pure shown bands at 28, 48 and 93 kDa by SDS-PAGE, with an incomplete dissociation of the last species despite trying several reduction conditions. By preparative electrophoresis under different conditions, three species were observed too, in all fractions one band at 28 kDa on Tricine-PAGE in reducing and no reducing conditions were found.Amino acid composition, carbohydrate content, thermal stability and Ca2+and Mn2+requirements were determined. N-acetylgalactosamine (GalNAc) and desialylated mucins inhibited the agglutinant activity on human cells. Fetuin inhibited hemagglutination of rabbit erythrocytes.Conclusion: A new lectin was isolated and characterized from L. bullata seeds, it recognizes T/Tn antigen and shows some similarities with other Lamiaceae lectins.

scholarly journals Purification and Characterization of Peroxidase From Anthracnose Disease Infected Papaya (Carica papaya L.)

2014 ◽  
Vol 6 (2) ◽  
pp. 49-57 ◽  
Author(s):  
L Bari ◽  
P Hassan ◽  
N Absar ◽  
S Khatun ◽  
MI Hossain
Keyword(s):  
Ammonium Sulphate ◽  
Gel Filtration ◽  
Potassium Cyanide ◽  
Ammonium Sulphate Precipitation ◽  
Reducing Conditions ◽  
Sds Page ◽  
Peroxidase Enzyme ◽  
Km Value ◽  
Temperature Optima

Peroxidase enzyme was isolated and purified from the pulp of disease infected ripen papaya of local variety by 90% ammonium sulphate precipitation, chromatography on DEAEcellulose followed by hydrophobic chromatography on Phenyl Sepharose CL-4B and the purifications achieved was about 7.2 fold with 2.5% recovery. The purified enzyme was homogeneous as judged by polyacrylamide slab gel electrophoresis. The purified enzyme had a Mr of about 55,000 and 50 000 as determined by gel filtration on Sephadex G-100 and SDS-PAGE, respectively. The molecular mass of the enzyme was found to be very similar under both reducing and non-reducing conditions indicating that the enzyme contains no subunit. The enzyme has the following characteristics: pH optima at 6.0, temperature optima around 38°C, enzyme activity was found to be strongly inhibited in the presence of potassium cyanide and Fe+2 while the activity was found to be remarkably increased in the presence of ammonium sulphate. The Km value for the peroxidase obtained with pyrogallol as substrate was 0.027 mM. DOI: http://dx.doi.org/10.3329/bjmb.v6i2.17643 Bangladesh J Med Biochem 2013; 6(2): 49-57

scholarly journals Characterization of a membrane protease from rat submaxillary-gland mitochondria that possess thrombin-like activity

1996 ◽  
Vol 313 (1) ◽  
pp. 193-199 ◽  
Author(s):  
Mausumi BHARADWAJ ◽  
Dwaipayan BHARADWAJ ◽  
Ratha N. HATI
Keyword(s):  
Trypsin Inhibitor ◽  
Gel Filtration ◽  
Submaxillary Gland ◽  
Kinetic Studies ◽  
Lima Bean ◽  
Maximum Activity ◽  
Reducing Conditions ◽  
Sds Page ◽  
Bean Trypsin Inhibitor

A membrane protease possessing thrombin-like activity was purified to homogeneity from mitochondria of rat submaxillary gland. The molecular mass of the enzyme was determined to be 45 kDa by SDS/PAGE under reducing conditions and by gel filtration on a Sephadex G-100 column. The enzyme is a glycoprotein and has an isoelectric point of 3.25. Maximum activity was observed at pH 10.5. Inhibition by di-isopropyl fluorophosphate, benzamidine, aprotinin and antipain suggested the enzyme to be a serine protease. Other inhibitors such as EDTA, soya-bean trypsin inhibitor, lima-bean trypsin inhibitor, TosLysCH2Cl and chymostatin did not alter the activity. The enzyme showed affinity towards different synthetic substrates (p-nitroanilide derivatives) containing arginine at the P1 position. Kinetic studies revealed that kcat./Km was highest with the substrate N-Bz-Phe-Val-Arg-p-nitroanilide. The enzyme exhibits significant plasma-coagulating activity. The coagulation initiated by the enzyme was not altered by concanavalin A, indicating that the carbohydrate moiety of the enzyme is not essential for this reaction. Further, this enzyme can catalyse the formation of fibrin clots from purified fibrinogen, which describes its thrombin-like activity. However, an antibody raised against the purified enzyme inhibited the plasma-clotting as well as fibrinogen-clotting activity of the enzyme. Fibrinogen coagulation by the enzyme was blocked in the presence of aprotinin, a protease inhibitor. Release of fibrinopeptides A and B from bovine fibrinogen by the enzyme has been shown by HPLC analysis. Our studies reveal that the enzyme reported here differs from trypsin, chymotrypsin and other mitochondrial proteases reported so far.

Characterization of monoclonal antibodies to trichocyst antigens in Paramecium

1988 ◽  
Vol 91 (2) ◽  
pp. 191-199
Author(s):  
A.K. Fok ◽  
R.P. Olegario ◽  
M.S. Ueno ◽  
R.D. Allen
Keyword(s):  
Monoclonal Antibodies ◽  
Small Variation ◽  
Immunogold Labelling ◽  
Immunofluorescence Assay ◽  
Outer Edge ◽  
Thin Sections ◽  
Reducing Conditions ◽  
Sds Page ◽  
The Family

Ten mouse monoclonal antibodies (mAbs) were raised against trichocyst contaminants present in crude or enriched lysosome fractions of Paramecium multimicronucleatum. Using an indirect immunofluorescence assay (IFA) and immunogold labelling on frozen thin sections, epitopes were located on the outer edge, cortex and the core of the trichocyst body, as well as the sheath covering the tip. Except for the two on the tip, epitopes were reactive after SDS-PAGE under non-reducing conditions. Four mAbs (131C1E8, A1-3, A16-2, D7) were directed to a trio of bands of 37, 34 and 29 (x 10(3] Mr from the beaded or meshlike trichocyst body sheath. A fifth mAb (135B9E7), directed to epitopes on the cortex inside the beaded body sheath, reacted strongly with the 37 and 34 bands, but weakly with the 29 × 10(3) Mr band. The last three mAbs (270D5, 22D7F2, D8) were reactive with one or more of three families of antigens found on the trichocyst core. mAb 270D5 reacted mainly with the 34 and 29 (x 10(3] Mr bands of the family containing the above trio, while mAb 22C7F2 reacted consistently with the 47 × 10(3) band of the higher Mr family but variably with both the trio of bands and the 17 × 10(3) band of the lower Mr family. mAb D8, which was directed to epitopes on the trichocyst core and small vesicles in the endoplasm, reacted only with the 29 × 10(3) Mr band. The mAbs were cross-reactive with the trichocysts of P. primaurelia, P. tetraurelia, P. caudatum and P. calkinsi with some small variation in blotting patterns.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Purification and characterization of subcomponent C1q of the first component of bovine complement

1979 ◽  
Vol 177 (2) ◽  
pp. 531-540 ◽  
Author(s):  
R. Duncan Campbell ◽  
Nuala A. Booth ◽  
John E. Fothergill
Keyword(s):  
Sodium Dodecyl ◽  
Molar Ratio ◽  
High Yield ◽  
Molecular Characteristics ◽  
Haemolytic Activity ◽  
Reducing Conditions ◽  
Equilibrium Sedimentation ◽  
Triple Helices ◽  
Polypeptide Chains

Bovine C1q, a subcomponent of the first component of complement, was purified in high yield by a combination of euglobulin precipitation, and ion-exchange and molecularsieve chromatography on CM-cellulose and Ultrogel AcA 34. Approx. 12–16mg can be isolated from 1 litre of serum, representing a yield of 13–18%. The molecular weight of undissociated subcomponent C1q, as determined by equilibrium sedimentation, is 430000. On sodium dodecyl sulphate/polyacrylamide gels under non-reducing conditions, subcomponent C1q was shown to consist of two subunits of mol.wts. 69000 and 62000 in a molar ratio of 2:1. On reduction, the 69000-mol.wt. subunit gave chains of mol.wts. 30000 and 25000 in equimolar ratio, and the 62000-mol.wt. subunit decreased to 25000. The amino acid composition, with a high value for glycine, and the presence of hydroxyproline and hydroxylysine, suggests that there is a region of collagen-like sequence in the molecule. This is supported by the loss of haemolytic activity and the degradation of the polypeptide chains of subcomponent C1q when digested by collagenase. All of these molecular characteristics support the structure of six subunits, each containing three different polypeptide chains, with globular heads connected by collagen triple helices as proposed by Reid & Porter (1976) (Biochem. J.155, 19–23) for human subcomponent C1q. Subcomponent C1q contains approx. 9% carbohydrate; analysis of the degree of substitution of the hydroxylysine residues revealed that 91% are modified by the addition of the disaccharide unit Gal-Glc. Bovine subcomponent C1q generates full C1 haemolytic activity when assayed with human subcomponents C1r and C1s.

scholarly journals Formation and Characterization of Lactoferrin-Hyaluronic Acid Conjugates and Their Effects on the Storage Stability of Sesamol Emulsions

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3291 ◽  
Author(s):  
Runhua Liu ◽  
Jinhong Zhang ◽  
Caicai Zhao ◽  
Xiang Duan ◽  
David McClements ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Molar Ratio ◽  
Optimum Stability ◽  
Sds Page ◽  
Amine Groups ◽  
Physical And Chemical ◽  
Covalent Conjugates

The purpose of this study was to fabricate biopolymer conjugates from lactoferrin (LF) and hyaluronic acid (HA) and then to investigate their potential as emulsifiers for forming sesamol-loaded emulsions. Initially, LF-HA covalent conjugates were formed using the carbodiimide coupling method in aqueous solutions at pH = 4.5, and then the nature of the conjugates was investigated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), Fourier Transform Infrared Spectroscopy (FTIR) spectroscopy, and fluorescence spectroscopy. The results demonstrated the formation of an amide link between the amine groups of LF and the carboxyl groups of HA. Sesamol emulsions were prepared using the LF-HA conjugates as emulsifiers and their stability was determined. The conjugates improved both the physical and chemical stability of the emulsions during storage. Optimum stability of the emulsion was obtained at a LF-to-HA molar ratio of 2:1. Our results suggest that LF-HA conjugates may be effective emulsifiers for use in food stuffs and other applications.

Functional Characterization of PM6/13, a β3-specific (GPIIIa/CD61) Monoclonal Antibody that Shows Preferential Inhibition of Fibrinogen Binding over Fibronectin Binding to Activated Human Platelets

1998 ◽  
Vol 79 (01) ◽  
pp. 177-185 ◽  
Author(s):  
Ashia Siddiqua ◽  
Michael Wilkinson ◽  
Vijay Kakkar ◽  
Yatin Patel ◽  
Salman Rahman ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Platelet Aggregation ◽  
Platelet Rich Plasma ◽  
Functional Characterization ◽  
Human Platelets ◽  
Western Blots ◽  
Activated Platelets ◽  
Reducing Conditions ◽  
Fibronectin Binding

SummaryWe report the characterization of a monoclonal antibody (MAb) PM6/13 which recognises glycoprotein IIIa (GPIIIa) on platelet membranes and in functional studies inhibits platelet aggregation induced by all agonists examined. In platelet-rich plasma, inhibition of aggregation induced by ADP or low concentrations of collagen was accompanied by inhibition of 5-hydroxytryptamine secretion. EC50 values were 10 and 9 [H9262]g/ml antibody against ADP and collagen induced responses respectively. In washed platelets treated with the cyclooxygenase inhibitor, indomethacin, PM6/13 inhibited platelet aggregation induced by thrombin (0.2 U/ml), collagen (10 [H9262]g/ml) and U46619 (3 [H9262]M) with EC50 = 4, 8 and 4 [H9262]g/ml respectively, without affecting [14C]5-hydroxytryptamine secretion or [3H]arachidonate release in appropriately labelled cells. Studies in Fura 2-labelled platelets revealed that elevation of intracellular calcium by ADP, thrombin or U46619 was unaffected by PM6/13 suggesting that the epitope recognised by the antibody did not influence Ca2+ regulation. In agreement with the results from the platelet aggregation studies, PM6/13 was found to potently inhibit binding of 125I-fibrinogen to ADP activated platelets. Binding of this ligand was also inhibited by two other MAbs tested, namely SZ-21 (also to GPIIIa) and PM6/248 (to the GPIIb-IIIa complex). However when tested against binding of 125I-fibronectin to thrombin stimulated platelets, PM6/13 was ineffective in contrast with SZ-21 and PM6/248, that were both potent inhibitors. This suggested that the epitopes recognised by PM6/13 and SZ-21 on GPIIIa were distinct. Studies employing proteolytic dissection of 125I-labelled GPIIIa by trypsin followed by immunoprecipitation with PM6/13 and analysis by SDS-PAGE, revealed the presence of four fragments at 70, 55, 30 and 28 kDa. PM6/13 did not recognize any protein bands on Western blots performed under reducing conditions. However Western blotting analysis with PM6/13 under non-reducing conditions revealed strong detection of the parent GP IIIa molecule, of trypsin treated samples revealed recognition of an 80 kDa fragment at 1 min, faint recognition of a 60 kDa fragment at 60 min and no recognition of any product at 18 h treatment. Under similar conditions, SZ-21 recognized fragments at 80, 75 and 55 kDa with the 55kDa species persisting even after 18 h trypsin treatment. These studies confirm the epitopes recognised by PM6/13 and SZ-21 to be distinct and that PM6/13 represents a useful tool to differentiate the characteristics of fibrinogen and fibronectin binding to the GPIIb-IIIa complex on activated platelets.

Characterization of Venoms of Deinagkistrodon acutus and Bungarus multicinctus Using Proteomics and Peptidomics

2020 ◽  
Vol 17 (3) ◽  
pp. 241-254
Author(s):  
Yaqiong Zhang ◽  
Zhiping Jia ◽  
Yunyang Liu ◽  
Xinwen Zhou ◽  
Yi Kong
Keyword(s):  
Snake Venom ◽  
Protein Families ◽  
Traditional Medicines ◽  
Phospholipases A2 ◽  
Inhibitory Peptides ◽  
Sds Page ◽  
Deinagkistrodon Acutus ◽  
Venom Proteins ◽  
Proteins And Peptides

Background: Deinagkistrodon acutus (D. acutus) and Bungarus multicinctus (B. multicinctus) as traditional medicines have been used for hundreds of years in China. The venoms of these two species have strong toxicity on the victims. Objective: The objective of this study is to reveal the profile of venom proteins and peptides of D. acutus and B. multicinctus. Method: Ultrafiltration, SDS-PAGE coupled with in-gel tryptic digestion and Liquid Chromatography- Electrospray Ionization-Tandem Mass Spectrometry (LC-ESI-MS/MS) were used to characterize proteins and peptides of venoms of D. acutus and B. multicinctus. Results: In the D. acutus venom, 67 proteins (16 protein families) were identified, and snake venom metalloproteinases (SVMPs, 38.0%) and snake venom C-type lectins (snaclecs, 36.7%) were dominated proteins. In the B. multicinctus venom, 47 proteins (15 protein families) were identified, and three-finger toxins (3FTxs, 36.3%) and Kunitz-type Serine Protease Inhibitors (KSPIs, 32.8%) were major components. In addition, both venoms contained small amounts of other proteins, such as Snake Venom Serine Proteinases (SVSPs), Phospholipases A2 (PLA2s), Cysteine-Rich Secreted Proteins (CRISPs), 5'nucleotidases (5'NUCs), Phospholipases B (PLBs), Phosphodiesterases (PDEs), Phospholipase A2 Inhibitors (PLIs), Dipeptidyl Peptidases IV (DPP IVs), L-amino Acid Oxidases (LAAOs) and Angiotensin-Converting Enzymes (ACEs). Each venom also had its unique proteins, Nerve Growth Factors (NGFs) and Hyaluronidases (HYs) in D. acutus, and Cobra Venom Factors (CVFs) in B. multicinctus. In the peptidomics, 1543 and 250 peptides were identified in the venoms of D. acutus and B. multicinctus, respectively. Some peptides showed high similarity with neuropeptides, ACE inhibitory peptides, Bradykinin- Potentiating Peptides (BPPs), LAAOs and movement related peptides. Conclusion: Characterization of venom proteins and peptides of D. acutus and B. multicinctus will be helpful for the treatment of envenomation and drug discovery.

Sign in / Sign up

Export Citation Format

Share Document