Investigation of the free heavy chain homodimers of a monoclonal antibody

2018 ◽  
Vol 34 (3) ◽  
pp. 738-745 ◽  
Author(s):  
Hyo Helen Chung ◽  
Lynette Buck ◽  
Kristi Daris ◽  
Brent Welborn ◽  
Quanzhou Luo ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Heavy Chain ◽  
Free Heavy Chain

scholarly journals A monoclonal antibody recognizing an icosapeptide sequence in the heavy chain of human factor XII inhibits surface-catalyzed activation.

1987 ◽  
Vol 262 (21) ◽  
pp. 10140-10145
Author(s):  
R.A. Pixley ◽  
L.G. Stumpo ◽  
K. Birkmeyer ◽  
L. Silver ◽  
R.W. Colman
Keyword(s):  
Monoclonal Antibody ◽  
Heavy Chain ◽  
Human Factor ◽  
Factor Xii

scholarly journals Contractile activity is required for the expression of neonatal myosin heavy chain in embryonic chick pectoral muscle cultures.

1986 ◽  
Vol 103 (6) ◽  
pp. 2153-2161 ◽  
Author(s):  
L C Cerny ◽  
E Bandman
Keyword(s):  
Monoclonal Antibody ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Contractile Activity ◽  
Pectoral Muscle ◽  
Chicken Muscle ◽  
High K ◽  
Muscle Cultures ◽  
Spontaneous Contractions

The expression of neonatal myosin heavy chain (MHC) was examined in developing embryonic chicken muscle cultures using a monoclonal antibody (2E9) that has been shown to be specific for that isoform (Bandman, E., 1985, Science (Wash. DC), 227: 780-782). After 1 wk in vitro some myotubes could be stained with the antibody, and the number of cells that reacted with 2E9 increased with time in culture. All myotubes always stained with a second monoclonal antibody that reacted with all MHC isoforms (AG19) or with a third monoclonal antibody that reacted with the embryonic but not the neonatal MHC (EB165). Quantitation by ELISA of an extract from 2-wk cultures demonstrated that the neonatal MHC represented between 10 and 15% of the total myosin. The appearance of the neonatal isoform was inhibited by switching young cultures to medium with a higher [K+] which has been shown to block spontaneous contractions of myotubes in culture. Furthermore, if mature cultures that reacted with the neonatal antibody were placed into high [K+] medium, neonatal MHC disappeared from virtually all myotubes within 3 d. The effect of high [K+] medium was reversible. When cultures maintained in high [K+] medium for 2 wk were placed in standard medium, which permitted the resumption of contractile activity, within 24 h cells began to react with the neonatal specific antibody, and by 72 h many myotubes were strongly positive. Since similar results were also obtained by inhibiting spontaneous contractions with tetrodotoxin, we suggest that the development of contractile activity is not only associated with the maturation of myotubes in culture, but may also be the signal that induces the expression of the neonatal MHC.

Intact HLA Not β2m-free Heavy Chain-Specific HLA Class I Antibodies Are Predictive of Graft Failure

2009 ◽  
Vol 88 (2) ◽  
pp. 226-230 ◽  
Author(s):  
Junchao Cai ◽  
Paul I. Terasaki ◽  
Naomi Anderson ◽  
Nils Lachmann ◽  
Constanze Schönemann
Keyword(s):  
Heavy Chain ◽  
Graft Failure ◽  
Hla Class I ◽  
Class I ◽  
Free Heavy Chain

ANTIBODY TARGETED FIBRINOLYSIS

1987 ◽  
Author(s):  
Edgar Haber ◽  
Marchall T Runge ◽  
Christoph Bode ◽  
Betsy Branscomb ◽  
Janet Schnee
Keyword(s):  
Monoclonal Antibody ◽  
Fusion Protein ◽  
Cell Line ◽  
Heavy Chain ◽  
Specific Antibody ◽  
Plasminogen Activators ◽  
Amino Terminus ◽  
Beta Chain ◽  
Western Blots ◽  
Competitive Binding Assay

Chemical conjugates of fibrin-specificantibodies and plasminogen activators. Urokinase or tPA were linked covalently toamonoclonal antibody specific for the amino terminus of the beta chain of human fibrin (59D8) by means of the unidirectionalcross-linking reagent SPDP. The fibrinolytic potency of the conjugates at equal amidolytic activities was compared to the native plasminogen activators in an assay measuring lysis of 1251-fibrin monomer covalently linked to Sepharose CL-4B. Urokinase was least potent, tPA exhibited a 10fold increase in fibrinolysis whereas both the urokinase and tPA antibody conjugates and a urokinase-Fab conjugate were 250fold more potent than urokinase and 25 fold more potent than tPA. Enhanced fibrinolysis was fully inhibited by b peptide indicating its dependence on antigen binding. In a plasma assay conjugates of tPA orUK to antibody produced a 3.2- to 4.5-fold enhancement in clot lysis in human plasma over that of the respective unconjugated plasminogen activator. However, the UK-59D8 conjugate was only as potent as tPAalone. Antibody-conjugated tPA or UK consumed less fibrinogen, alpha 2-antiplasminand plasminogen than did the unconjugatedactivators, at equipotent thrombolytic concentrations. In a quantitative rabbit thrombolysis model, the activity of the purified conjugate was compared with that oftPA alone and that of a conjugate betweentPA and a digoxin-specific monoclonal antibody. After correction for spontaneous lysis, tPA-59D8 was shown to be 2.8 to,9.6times more potent than tPA alone. Unconjugated tPA and tPA-digoxin were equipotent.At equivalent thrombolytic concentrations, tPA-59D8 degraded less fibrinogen and consumed less alpha 2-antiplasmin than did tPA alone. These results suggest that tPA can be efficiently directed to the site of a thrombus by conjugation to an antifibrin monoclonal antibody, resulting in both more potent and more selective thrombolysis.A recombinant fusion protein comprising a fibrin-specific antibody site and theB chain of tPA. The rearranged 59D8 heavychain gene was cloned and combined in theexpression vector pSV2gpt withsequence coding for a portion of the Gamma 2b constant region and the catalytic beta chain of t-PA. This construct was transfected into heavy chain loss variant cells derived from the 59D8 hybridoma. Recombinant protein was purified by affinitychromatography and analyzed with Western blots. These revealed a 65-kD heavy chain-t-PA fusion protein that is secreted in association with the 59D8 light chain in the form of a 170-kD disulfide linked dimer. A chromogenic substrate assay showed the fusion protein to have 70 percent of the peptidolytic activity of native t-PA and to activate plasminogen as efficiently as t-PA. In a competitive binding assay, reconstituted antibody was shown to have a binding profile similar to that of native 59D8. Thus by recombinant techniques we have produced a novel hybrid protein capable of high affinity fibrin binding andplasminogen activation.Chemical conjugates between a fibrin-specific and a tPA-specific antibody. A heteroantibody duplex (duplex) with specificities for both tPA and fibrin was synthesized by conjugating iminothiolane-modified anti-tPA monoclonal antibody (TCL8) toantifibrin antibody 59D8. Addition of both duplex and tPA to a plasma clot assay gave more lysis (200 units produced 23.1 lysis; 400 units, 29.5 lysis) than did tPAalone (200 units, 1.8% lysis; 400 units,19% lysis). Despite increased potency associated with duplex addition, fibrinogen and alpha-2-antiplasmin levels at equal tPA concentrations did not differ. Thus, itis possible to concentrate tPA (added separately) to the site of a thrombus in plasma using a heteroantibody duplex with specificities for both tPA and fibrin.Biosynthetically produced heteroduplexantibodies that are both fibin and tPA-specific. The bispecific antibodies were prepared in two ways. First, polyethylene glycol-mediated fusions were performed with two different hybridoma cell lines: anti-fribrin b chain producer, 59D8 and anti-tPA producer, TCL8. TCL8 cells were selected for HPRT-minus variants and then fused with TK-deficient 59D8 cells. One cell line, F36.23, possessed both anti-human fibrin and anti-human t-PA immunoreactivities. A second method yielded another bispecific antibody, F32.1. This cell line was selected after fusing TCL8 (HPRT-minus) cells with spleen cells from a mouseimmunized with a fibrin-like peptide corresponding to the amino terminus of fibrinalpha-chains. Affinity-purified F32.1 andF36.23 retained anti-fibrin and anti-t-PAactivity and enhanced fibrinolytic potency of tPA by a factor of 10.

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