scholarly journals Synthesis and characterization of a biotinylated organophosphorus ester for detection and affinity purification of a brain serine esterase: neuropathy target esterase

1994 ◽  
Vol 301 (2) ◽  
pp. 551-556 ◽  
Author(s):  
P Glynn ◽  
D J Read ◽  
R Guo ◽  
S Wylie ◽  
M K Johnson
Keyword(s):  
Affinity Purification ◽  
Order Rate Constant ◽  
Single Step ◽  
Neuropathy Target Esterase ◽  
Serine Esterase ◽  
Western Blots ◽  
Sds Page ◽  
Covalent Inhibitors ◽  
Serine Esterases

We have synthesized a novel stable precursor, saligenin phosphorotrichloridate, which, on reaction with N-monobiotinyldiamines, generates a series of biotinylated covalent inhibitors of serine esterases. A homologue designated S9B [1-(saligenin cyclic phospho)-9-biotinyldiaminononane] was selected to allow detection and rapid isolation of neuropathy target esterase (NTE). This enzyme is the primary target site for those organophosphorus esters (OPs) which cause delayed neuropathy. NTE comprises about 0.03% of the total protein in brain microsomal fractions and has resisted purification attempts over many years. S9B is a potent progressive inhibitor of NTE esteratic activity (second-order rate constant 1.4 x 10(7) M-1.min-1). Incubation of S9B with brain microsomes led to specific covalent labelling of NTE as determined by detection of a biotinylated 155 kDa polypeptide on Western blots. Specificity of S9B labelling was further demonstrated by inhibition with the neuropathic OP mipafox. Biotinyl-NTE in SDS-solubilized S9B-labelled microsomes was adsorbed on to avidin-Sepharose and subsequently eluted, yielding a fraction enriched approx. 1000-fold in NTE by a single step with recoveries of 30%. Essentially pure NTE was obtained after separation from two endogenous biotinylated polypeptides (120 and 70 kDa) in avidin-Sepharose eluates by preparative SDS/PAGE. Other biotinylated saligenin phosphoramidates derived from the same precursor may be useful for detection and isolation of other serine esterases and proteinases.

scholarly journals Expression of perforin and serine esterases by human gamma/delta T cells.

1991 ◽  
Vol 173 (2) ◽  
pp. 499-502 ◽  
Author(s):  
H Koizumi ◽  
C C Liu ◽  
L M Zheng ◽  
S V Joag ◽  
N K Bayne ◽  
...  
Keyword(s):  
T Cells ◽  
Nk Cells ◽  
Mechanism Of Action ◽  
Lak Cells ◽  
Gamma Delta T Cells ◽  
Serine Esterase ◽  
Gamma Delta ◽  
Western Blots ◽  
Polyclonal Antisera ◽  
Serine Esterases

gamma/delta T cells have recently been described in association with a number of disorders, including autoimmune diseases. gamma/delta T cells are thought to play a cytotoxic role, but their mechanism of action is not known. Several granule mediators of cytotoxicity, including a pore-forming protein (perforin), and a family of serine esterases, have been isolated from cytotoxic T lymphocytes (CTL), lymphokine-activated killer (LAK) cells, and natural killer (NK) cells. We demonstrate here that gamma/delta T cells also express these mediators. Northern blots show that gamma/delta T cells express perforin, serine esterase 1 (SE 1), and SE 2. Three polyclonal antisera - raised against murine perforin, a peptide composed of amino acids 1-34 of human perforin, and human peforin expressed in bacteria - all reacted with a 70-kD protein in gamma/delta T cells on Western blots. Immunostaining with antiperforin antisera shows that primary gamma/delta T cells also contain perforin. Electron microscopy reveals that the granules of gamma/delta T cells resemble those of CTL, LAK, and NK cells. Gamma/delta T cells also resemble LAK cells in possessing inclusion bodies in their nuclei. These results imply that gamma/delta T cells resemble other cytolytic lymphocytes in their mechanism of action.

scholarly journals Affinity purification and refined structural characterization of terminal deoxynucleotidyltransferase

1985 ◽  
Vol 231 (1) ◽  
pp. 105-113 ◽  
Author(s):  
S A Fuller ◽  
A Philips ◽  
M S Coleman
Keyword(s):  
Monoclonal Antibody ◽  
Specific Binding ◽  
Affinity Purification ◽  
Single Step ◽  
Immunoaffinity Column ◽  
Tissue Slices ◽  
Terminal Transferase ◽  
Antigenic Sites ◽  
High Binding Affinity

A total of 56 stable murine hybridoma monoclones that produce homogeneous antibodies against human or calf terminal deoxynucleotidyltransferase have been established. All of the antibodies exhibited specific binding to various Mr forms of terminal transferase and eight possessed neutralizing activity. Results are presented that permitted characterization of ten of these antibodies with respect to their immunoglobulin class, their recognition of calf or human terminal-transferase Mr species by immunoblotting techniques and their recognition of distinct antigenic sites. Terminal transferase was purified in a single step by using an immunoaffinity column constructed with a monoclonal antibody exhibiting a high binding affinity for the enzyme. Single monoclonal antibodies were also used to bind selectively to terminal-transferase antigen in tissue slices and individual cells.

scholarly journals PROPERDIN FACTOR D: CHARACTERIZATION OF ITS ACTIVE SITE AND ISOLATION OF THE PRECURSOR FORM

1974 ◽  
Vol 139 (2) ◽  
pp. 355-366 ◽  
Author(s):  
Douglas T. Fearon ◽  
K. Frank Austen ◽  
Shaun Ruddy
Keyword(s):  
Active Site ◽  
Gel Filtration ◽  
Serine Esterase ◽  
Factor B ◽  
Alternate Pathway ◽  
Serine Esterases ◽  
Definition Of ◽  
Chromatographic Isolation

The activity of properdin factor D was measured by the generation of the hemolytically active cellular intermediate, EAC43B(D), bearing the C3b-dependent alternate pathway C3 convertase. Treatment of factor D with DFP prevented formation of EAC43B(D); thus, a serine esterase is essential for the generation of the alternate pathway C3 convertase, a situation analogous to the role of C1 in the formation of the classical C3 convertase, C42. The definition of factor D as a serine esterase prompted a search for its proenzyme form, and resulted in the chromatographic isolation from plasma of a single peak of trypsin-inducible factor D activity, distinct from activated factor D. Analytical gel filtration indicated an apparent mol wt of 25,000. This protein from which trypsin elaborated factor D activity, as assessed by the formation of EAC43B(D), the generation of the CoVF-dependent C3 convertase, and the cleavage of factor B in the presence of C3b, was designated "precursor factor D." The DFP resistance of precursor factor D, and the susceptibility of its trypsin-activated form to inactivation by DFP is analogous to the behavior of other plasma serine esterases, including C1.

scholarly journals Characterization of phospholipid methylation in rat brain myelin

1995 ◽  
Vol 307 (1) ◽  
pp. 239-244 ◽  
Author(s):  
V Tsvetnitsky ◽  
L Auchi ◽  
A Nicolaou ◽  
W A Gibbons
Keyword(s):  
Rat Brain ◽  
Affinity Purification ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Methyl Transferase ◽  
Sds Page ◽  
Triton X ◽  
Predominant Product

Highly purified rat brain myelin was solubilized in Triton X-100 and myelin phospholipid N-methyltransferase was characterized. The enzyme activities were separated by isoelectric focusing and ion-exchange chromatography. The phospholipid methyl-transferase has shown at least four peaks of activity with pIapp. values of 4.5, 5.2, 6.2 and 8.4. After affinity purification each of these activities revealed a close set of bands of approx. 65 kDa on SDS/PAGE. These data together with those from preparative SDS/PAGE separations suggested that rat brain myelin contains three acidic and at least one basic phospholipid-methylating isoenzymes and that the major isoenzyme in each case is approx. 65 kDa in size. While the predominant product of the reaction catalysed by all detected isoforms was monomethylated phosphatidylethanolamine, the least acidic isoform (pIapp. 6.2) also formed about 20% phosphatidylcholine, suggesting that these isoenzymes may play different roles in vivo.

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.

Rapid, Refined, and Robust Method for Expression, Purification, and Characterization of Recombinant Human Amyloid-beta M1-42

2019 ◽  
Author(s):  
Priya Prakash ◽  
Travis Lantz ◽  
Krupal P. Jethava ◽  
Gaurav Chopra
Keyword(s):  
Amyloid Beta ◽  
Western Blots ◽  
Force Microscopy ◽  
E Coli ◽  
Atomic Force ◽  
Set Up ◽  
Short Time

Amyloid plaques found in the brains of Alzheimer’s disease (AD) patients primarily consists of amyloid beta 1-42 (Ab42). Commercially, Ab42 is synthetized using peptide synthesizers. We describe a robust methodology for expression of recombinant human Ab(M1-42) in Rosetta(DE3)pLysS and BL21(DE3)pLysS competent E. coli with refined and rapid analytical purification techniques. The peptide is isolated and purified from the transformed cells using an optimized set-up for reverse-phase HPLC protocol, using commonly available C18 columns, yielding high amounts of peptide (~15-20 mg per 1 L culture) in a short time. The recombinant Ab(M1-42) forms characteristic aggregates similar to synthetic Ab42 aggregates as verified by western blots and atomic force microscopy to warrant future biological use. Our rapid, refined, and robust technique to purify human Ab(M1-42) can be used to synthesize chemical probes for several downstream in vitro and in vivo assays to facilitate AD research.

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.

Characterization of Glycoprotein Fraction from Carp Pituitaries Isolated Using Concanavalin A as the Affinity Ligand

1998 ◽  
Vol 63 (3) ◽  
pp. 434-440 ◽  
Author(s):  
Irena Hulová ◽  
Jana Barthová ◽  
Helena Ryšlavá ◽  
Václav Kašička
Keyword(s):  
Concanavalin A ◽  
Reversed Phase ◽  
Amino Acid Sequences ◽  
Gel Chromatography ◽  
Affinity Ligand ◽  
Sds Page ◽  
Terminal Amino ◽  
Α And Β Subunits

Glycoproteins that have affinity to Concanavalin A were isolated from the acetone-dried pituitaries of common carp (Cyprinus carpio L.). Two fractions of glycoproteins were separated using gel chromatography on Superdex 75HR. The fraction with lower molecular weight (30 000) corresponding to the carp gonadotropin cGtH II was composed of two subunits as determined using SDS-PAGE. This protein fraction was further divided into four components using reversed-phase HPLC. Two fractions were pure α and β subunits of cGtH II as follows from immunodetection and from determination of N-terminal amino acid sequences. The other two were a mixture of α and β subunits as was also revealed by N-terminal analysis. Capillary electrophoresis was also used for characterization of isolated glycoproteins.

A p-Type PbS Quantum Dot Ink with Improved Stability for Solution Processable Optoelectronics

2021 ◽  
Author(s):  
Fiaz Ahmed ◽  
John Hardin Dunlap ◽  
Perry J. Pellechia ◽  
Andrew Greytak
Keyword(s):  
Quantum Dot ◽  
Ligand Exchange ◽  
Chemical Characterization ◽  
Single Step ◽  
Improved Stability ◽  
Solution Processable ◽  
P Type ◽  
Pbs Quantum Dot

A highly stable p-type PbS-QDs ink is prepared using a single-step biphasic ligand exchange route, overcoming instability encountered in previous reports. Chemical characterization of the ink reveals 3-mercaptopriopionic acid (MPA)...

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