La(SSB) - 1.0mg

La(SSB) - 1.0mg

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La ribonucleoprotein

SSB antigen

Sjögren's syndrome antigen B

Uniprot ID:  P10881
mRNA RefSeq:  NM_176665
Protein RefSeq:  NP_788838

Size: 1.0mg 
Source: Calf Thymus
Catalogue Number: ATL01-10

Product Information

Autoantibodies to the La (SSB) antigen can be detected in the sera of up to 87% of patients with primary or secondary Sjögren’s syndrome. The presence of anti-La (SSB) autoantibodies usually coincides with the presence of anti-Ro (SSA) autoantibodies, however the fact that anti-Ro autoantibodies are far more common in other rheumatological conditions such as systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD) suggests that anti-La is more specific for primary and secondary Sjögren’s than anti-Ro.

La (SSB) is a highly phosphorylated protein which migrates at about 50 kDa in SDS-polyacrylamide gel electrophoresis. Phosphorylated residues are present at the carboxy-terminal part of the protein. At least 8 isoelectric forms (pI range 6 to 7) have been identified.

The amino acid sequences of both human and bovine La (SSB) antigen have been determined by cDNA cloning and sequencing. Comparison of the two sequences shows 22 largely conservative amino acid substitutions with a total of 95% identity. Three regions of the La molecule (amino acids 1-107, 111-242 and 346-408) are thought to contain the major epitopes reactive with human anti-La sera. The broad cross-reactivity of patient sera with La (SSB) from diverse mammalian species indicates the presence of conserved epitopes. 

PDF-logo-dl La (SSB) datasheet

Clinical Indications

Sjögren's syndrome
Systemic Lupus Erythematosus
Neonatal Lupus syndrome


PDF-logo-dl  Material Safety Data Sheet


Molina, R. et al. (1986) Am. J. Med. 80, 23

Bloch, K.J. et al. (1965) Medicine 44, 187

Fox, R.I. et al. (1986) Arthritis Rheum. 29, 577

Aziz, K.E. et al. (1992) Aust. NZ J. Med. 22, 671

Manoussakis, M.N. et al. (1986) Scan. J. Rheumatol. 61, 89

Harley, J.B. et al. (1986) Arthritis Rheum. 29, 196

Craft, J.E. & Hardin, J.A. (1987) J. Rheumatol. 14 S13, 106

St. Clair, E.W. (1992) Rheum. Dis. Clin. N. America 18, 359

Harley, J.B. (1989) J. Autoimmun. 2, 383

Buyon, J.P. et al. (1989) J. Clin. Invest. 84, 627

Reichlin, M. (1986) J. Clin. Immunol. 6, 339

Wiascewk, C.A. & Reichlin, M. (1982) J. Clin. Invest. 69, 835

Stefano, J.E. (1984) Cell 36, 145

Gottlieb, E. & Steitz, J.A. (1989) EMBO J. 8, 841

Gottlieb, E. & Steitz, J.A. (1989) EMBO J. 8, 851

Maraia, R.J. et al. (1994) Mol. Cell Biol. 14, 2147

Maraia, R.J. (1996) Proc. Natl. Acad. Sci. USA 93, 3383

Bachmann, M. et al. (1990) Cell 60, 85

Chambers, J.C. et al. (1988) J. Biol. Chem. 263, 18043

Bachmann, M. et al. (1989) Mol. Cell Biochem. 85, 103

Pruijn, G.J.M. (1994) Man. Biol. Markers Dis. (Kluwer Acad.Publ.) B2/1-14

Pfeifle, J. et al. (1987) Biochim. Biophys. Acta 928, 217

Francoeur, A.M. et al. (1985) mol. Cell Biol. 5, 586

McNeilage, L.J. (1990) J. Immunol. 145, 3829

Chan, E.K.L. & Tan, E.M. (1987) J. Exp. Med. 166, 1627

Zhang, W. & Reichlin, M. (1996) Arthritis Rheum. 39, 522

Chan, E.K.L. et al. (1986) J. Immunol. 136, 3744

Chan, E.K.L. et al. (1989) Nucleic Acids Res. 17, 2233