scholarly journals Investigations of the structural function of the J chain in human immunoglobulin M

1973 ◽  
Vol 131 (4) ◽  
pp. 677-682 ◽  
Author(s):  
Manuel J. Ricardo ◽  
Franklin P. Inman
Keyword(s):  
Gel Filtration ◽  
Elution Curve ◽  
Immunoglobulin M ◽  
Human Immunoglobulin ◽  
Structural Function ◽  
J Chain ◽  
Mild Reduction

Human IgM molecules were treated with Na2SO3 or mercaptoethylamine in concentrations ranging from 2 to 14mm or 2 to 22mm respectively. The dissociation of IgM to IgMs varied from 0% to 100%. At the intermediate concentrations of either reagent the amount of freed J chains was less than expected. In an attempt to find an explanation for this, IgM was partially dissociated to IgMs with mercaptoethylamine. The IgMs isolated by gel filtration was divided according to the ascending and descending portions of the elution curve. These portions were treated with 24mm-mercaptoethylamine and analysed for the presence of J chains. Only the ascending portion contained free J chains. Thus, after mild reduction where not all the IgM molecules are dissociated to IgMs, some J chains remain covalently attached to some IgMs molecules although most of the J chains are freed. It was concluded that the J chain could serve as a ‘hitch’ for IgMs molecules forming intact IgM.

Site of attachment of J chain to human immunoglobulin M

Nature ◽  
1974 ◽  
Vol 249 (5458) ◽  
pp. 650-652 ◽  
Author(s):  
JIRI MESTECKY ◽  
RALPH E. SCHROHENLOHER
Keyword(s):  
Immunoglobulin M ◽  
Human Immunoglobulin ◽  
J Chain

scholarly journals The incorporation of J chain into reassembled human immunoglobulin M

1974 ◽  
Vol 137 (1) ◽  
pp. 79-83 ◽  
Author(s):  
Manuel J. Ricardo ◽  
Franklin P. Inman
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Immunoglobulin M ◽  
Human Immunoglobulin ◽  
Fc Fragment ◽  
Guanidinium Hydrochloride ◽  
J Chain ◽  
Disulphide Bonds ◽  
Complete Dissociation ◽  
Schlieren Pattern

Human IgM (immunoglobulin M) was reduced with 24mm-mercaptoethylamine. This atreatment resulted in complete dissociation to IgMs subunits and free J chain. Intr-subunit interchain disulphide bonds remained intact. The mixture then was encouraged to reoxidize. The schlieren pattern of the reoxidized mixture showed the presence of a considerable quantity of IgM in addition to residual IgMs. The isolated reassembled IgM did not dissociate in 5m-guanidinium hydrochloride. It apparently contained the same amount of covalently attached J chain as did native IgM. The J chain was a part of the high-molecular-weight Fc fragment obtained from the reassembled IgM.

scholarly journals The molecular weight of J chains derived from human immunoglobulin M

1974 ◽  
Vol 137 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Manuel J. Ricardo ◽  
John M. Brewer ◽  
Franklin P. Inman
Keyword(s):  
Molecular Weight ◽  
Saline Solution ◽  
Guanidine Hydrochloride ◽  
Average Molecular Weight ◽  
Sodium Dodecyl ◽  
Immunoglobulin M ◽  
Human Immunoglobulin ◽  
Average Weight ◽  
Polyacrylamide Gels ◽  
J Chain

J chain was isolated from sulphonated human immunoglobulin M molecules by electrophoresis on polyacrylamide gels. When determined by electrophoresis in sodium dodecyl sulphate–polyacrylamide gels, the molecular weight of the protein was about 27000. After suspension in 5m-guanidine hydrochloride solution for 21 days, two groups of three bands appeared on the gels. Most of the protein dissociated to components of molecular weight 15000. The molecular weight of purified J chain was also determined by ultracentrifugation. In borate–saline solution the average weight-average molecular weight was about 29000. The molecular weight slowly decreased upon prolonged exposure to guanidine hydrochloride, and after 14 days the minimum molecular weight was about 15000. Some association between chains still existed. These data suggest that J chain derived from the paraprotein exists in borate–saline solution as dimers held by strong non-covalent forces.

Accessibility of the promoter sequence in the J-chain gene is regulated by chromatin changes during B-cell differentiation

1986 ◽  
Vol 6 (11) ◽  
pp. 4031-4038
Author(s):  
M E Minie ◽  
M E Koshland
Keyword(s):  
B Cell ◽  
Early Stage ◽  
Promoter Sequence ◽  
Immunoglobulin M ◽  
Chain Gene ◽  
B Cell Differentiation ◽  
Cell Stage ◽  
J Chain ◽  
Lymphoid Lines ◽  
Nuclease Digestion

The gene for the immunoglobulin M (IgM)-polymerizing protein, the J chain, is activated when the mature B cell is triggered to secrete pentamer IgM. Activation of the gene was found to be associated with chromatin changes in a 240-base-pair region at the 5' end of the gene. Analyses of lymphoid lines showed that the 5' region was resistant to nuclease digestion at the immature B-cell stage; it became slightly more accessible in mature B cells and cells at an early stage in the IgM response and then displayed an open, hypersensitive structure in IgM-secreting cells. In addition, analyses of normal, mitogen-stimulated lymphocytes showed that the open hypersensitive structure was coinducible with J-chain gene expression. These results suggest that the 5' chromatin changes precede transcription, making control sequences within the site accessible to regulatory factors.

Effect of the presence or absence of J chain on expression of recombinant anti-Kell immunoglobulin M

2008 ◽  
Vol 18 (3) ◽  
pp. 167-174 ◽  
Author(s):  
J. E. M. Gilmour ◽  
S. Pittman ◽  
R. Nesbitt ◽  
M. L. Scott
Keyword(s):  
Immunoglobulin M ◽  
J Chain

Isolation of Murine and Human Immunoglobulin M and Murine Immunoglobulin D

2009 ◽  
Vol 85 (1) ◽  
Author(s):  
Sarah M. Andrew ◽  
Julie A. Titus ◽  
Ashok Amin ◽  
Richard Coico
Keyword(s):  
Immunoglobulin M ◽  
Human Immunoglobulin ◽  
Immunoglobulin D
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