Extended characterization of unpaired cysteines in an IgG1 monoclonal antibody by LC-MS analysis

2021 ◽  
Vol 622 ◽  
pp. 114172
Author(s):  
Xiaojuan Li ◽  
Li Xiao ◽  
Brent Kochert ◽  
Daniel P. Donnelly ◽  
Xinliu Gao ◽  
...  
1988 ◽  
Vol 251 (1) ◽  
pp. 17-22 ◽  
Author(s):  
P Fredman ◽  
L Mattsson ◽  
K Andersson ◽  
P Davidsson ◽  
I Ishizuka ◽  
...  

An IgG1 monoclonal antibody, Sulph I, reacting with sulphatide (3′-sulphogalactosylceramide), was produced by immunizing Balb/c mice with that glycolipid coated on Salmonella minnesota bacterial membrane. Radioimmunodetection of the binding of the monoclonal antibody to structurally related glycolipids adsorbed to microtitre plates or chromatographed on thin-layer plates was used to determine its binding epitope. The antibody showed similar binding avidity to three sulphated glycolipids: sulphatide, sulpholactosylceramide and seminolipid. Lysosulphatide did bind the antibody, but, compared with sulphatide, 30 times more antigen was needed for half-maximal binding. Bis(sulphogangliotriosyl)ceramide and bis-sulphogangliotetraosylceramide did not bind the antibody. These results suggest that terminal galactose-3-O-sulphate and part of the hydrophobic region of the glycolipid are recognized by the Sulph I antibody.


2017 ◽  
Vol 89 (15) ◽  
pp. 7915-7923 ◽  
Author(s):  
Chong-Feng Xu ◽  
Yunqiu Chen ◽  
Linda Yi ◽  
Tim Brantley ◽  
Brad Stanley ◽  
...  

Hybridoma ◽  
1998 ◽  
Vol 17 (2) ◽  
pp. 133-142 ◽  
Author(s):  
SONJOY MUKERJEE ◽  
MARC NASOFF ◽  
MICHAEL McKNIGHT ◽  
MARK GLASSY

mAbs ◽  
2013 ◽  
Vol 5 (1) ◽  
pp. 114-125 ◽  
Author(s):  
Liangjie Tang ◽  
Shanmuuga Sundaram ◽  
Jingming Zhang ◽  
Ping Carlson ◽  
Alice Matathia ◽  
...  

1998 ◽  
Vol 79 (01) ◽  
pp. 177-185 ◽  
Author(s):  
Ashia Siddiqua ◽  
Michael Wilkinson ◽  
Vijay Kakkar ◽  
Yatin Patel ◽  
Salman Rahman ◽  
...  

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.


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