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.

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.

Immunoaffinity Chromatography of Canine High-Molecular-Weight Renin: Partial Purification and Characterization

1983 ◽  
Vol 65 (2) ◽  
pp. 117-120 ◽  
Author(s):  
Fumihiko Ikemoto ◽  
Victor J. Dzau ◽  
Edgar Haber ◽  
Kazuo Takaori ◽  
Kenjiro Yamamoto
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Specific Activity ◽  
Immunoaffinity Chromatography ◽  
Partial Purification ◽  
Low Molecular Weight ◽  
Specific Method ◽  
Disulphide Bonds ◽  
Binding Substance ◽  
Molecular Weight Form

1. Canine high-molecular-weight renin (mol. wt. 60 000) is believed to be a complex of renin (low-molecular-weight form, mol. wt. 40 000) and renin-binding substance. The immunocross-reactivity of high-molecular-weight renin and low-molecular-weight renin was demonstrated by using antibodies specific to low-molecular-weight renin. 2. Immunoaffinity chromatography with renin-specific antibodies coupled to Sepharose provided a simple and specific method for isolation of high-molecular-weight renin. High-molecular-weight renin with a specific activity of 137 600 ng of ANG I h−1 mg−1 of protein (19.6 Goldblatt units/mg of protein) was obtained. 3. This high-molecular-weight renin was stable in dithiothreitol (25 mmol/l), suggesting that disulphide bonds may not be involved in the binding mechanism between low-molecular-weight renin and renin-binding substance. 4. However, exposure to low pH (3.0) resulted in conversion of high-molecular-weight renin into the low-molecular-weight form.

The interaction of bovine milk caseins with the detergent sodium dodecyl sulphate. I. The relationship between the composition and the size of the protein–detergent aggregate

1970 ◽  
Vol 37 (2) ◽  
pp. 245-257 ◽  
Author(s):  
G. C. Cheeseman ◽  
Joan Jeffcoat
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Sodium Dodecyl Sulphate ◽  
Sodium Dodecyl ◽  
Bovine Milk ◽  
Maximum Amount ◽  
Protein Molecules ◽  
The Individual ◽  
The Relationship ◽  
Complete Dissociation

SummaryStudy of the dissociation of high-molecular-weight aggregates of preparations of αs1-, β-, κ-, and para-κ-casein by the detergent, sodium dodecyl sulphate (SDS), showed that there are differences in the aggregation properties of the individual caseins. Binding of detergent led first to the dissociation of casein aggregates and then to further interaction with the casein molecules. The amounts of detergent required to give the minimum sized protein-detergent aggregate when expressed as mg/mg casein were similar for κ-, para-κ- and αs1-casein but much less for β-casein. However, expressed as mole/mole the requirement for κ- and αs1-casein was similar but was twice that found for para-κ- and β-casein. The maximum amount of SDS bound was about twice that required for complete dissociation of the aggregates for κ-, para-κ- and αs1-casein but was 13 times greater for β-casein.Complete dissociation of κ-casein aggregates by SDS alone was not possible due to the presence of aggregates formed by disulphide linkages. These aggregates, which consisted of 3±1 protein molecules, accounted for about one-third of the κ-casein in the preparations examined.

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

A preliminary study by gel filtration and ultracentrifugation of the interaction of bovine milk caseins with detergents

1968 ◽  
Vol 35 (3) ◽  
pp. 439-446 ◽  
Author(s):  
G. C. Cheeseman
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Sodium Dodecyl ◽  
Bovine Milk ◽  
Gel Filtration ◽  
Sedimentation Velocity ◽  
Disulphide Bonds ◽  
Reducing Conditions ◽  
Preliminary Study ◽  
The Individual

SummaryThe detergents sodium dodecyl sulphate and octyl phenoxy polyethoxyethanol interact with casein and cause dissociation of the high-molecular-weight casein aggregates. It is presumed that the detergent binds with hydrophobic regions in the casein molecule. The size of the complexes formed between detergents and αs1-casein, β-casein and κ-casein, as estimated by gel filtration and sedimentation velocity experiments, suggests that the caseins were complexed as monomers.During gel filtration under non-reducing conditions, detergent-κ-casein complexes were separated from other major components because of their conversion through formation of disulphide bonds into high-molecular-weight aggregates. This reaction, which did not occur in sedimentation velocity experiments, was presumably facilitated by the changes in the equilibrium between the individual caseins during gel filtration.Sedimentation velocity experiments showed that a ratio of about 40 detergent molecules to 1 casein molecule was required to give the smallest casein-detergent complex.

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