-transparent.png){kind=logo}
The sugar chains of IgG samples purified from sera of patients with rheumatoid arthritis (RA) contain many fewer galactose residues than those from sera of healthy individuals. Enzymatic studies revealed that the low galactose content in the IgGs of RA patients results from the reduced activity in the B cells of a galactosyltransferase (EC 2.4.1.90), which preferentially transfers galactose to asialo-agalacto-IgG. Asialo-agalacto-transferrin and asialo-ovine submaxillary mucin were also galactosylated by detergent-activated human B cell homogenates. However, no difference in the enzymatic activities toward these two acceptors was detected between the B cells from RA patients and from non-RA patients and healthy individuals. Enzyme kinetic studies revealed that an affinity of the galactosyltransferase in the B cells from RA patients was lowered for UDP-Gal but not for asialo-agalacto-IgG, while the affinities for UDP-Gal and asialo-agalacto-transferrin of the galactosyltransferase were not changed between the B cells from RA patients and from non-RA patients and healthy individuals in accordance with their enzyme activities. The results indicated that the reduced galactosyltransferase activity toward asialo-agalacto-IgG in the B cells from RA patients can be ascribed to the lowered affinity for UDP-Gal.
K Furukawa, and
K Matsuta, and
F Takeuchi, and
E Kosuge, and
T Miyamoto, and
A Kobata
December 1987,
Lancet (London, England),
K Furukawa, and
K Matsuta, and
F Takeuchi, and
E Kosuge, and
T Miyamoto, and
A Kobata
January 1988,
British journal of rheumatology,
K Furukawa, and
K Matsuta, and
F Takeuchi, and
E Kosuge, and
T Miyamoto, and
A Kobata
November 1998,
Glycoconjugate journal,
K Furukawa, and
K Matsuta, and
F Takeuchi, and
E Kosuge, and
T Miyamoto, and
A Kobata
April 2003,
Annals of the New York Academy of Sciences,
K Furukawa, and
K Matsuta, and
F Takeuchi, and
E Kosuge, and
T Miyamoto, and
A Kobata
January 1994,
Autoimmunity,
K Furukawa, and
K Matsuta, and
F Takeuchi, and
E Kosuge, and
T Miyamoto, and
A Kobata
August 1993,
The Journal of rheumatology,
K Furukawa, and
K Matsuta, and
F Takeuchi, and
E Kosuge, and
T Miyamoto, and
A Kobata
January 1995,
Advances in experimental medicine and biology,
K Furukawa, and
K Matsuta, and
F Takeuchi, and
E Kosuge, and
T Miyamoto, and
A Kobata
August 2004,
The Journal of rheumatology,
K Furukawa, and
K Matsuta, and
F Takeuchi, and
E Kosuge, and
T Miyamoto, and
A Kobata
January 2000,
Arthritis research,
K Furukawa, and
K Matsuta, and
F Takeuchi, and
E Kosuge, and
T Miyamoto, and
A Kobata
August 2007,
Autoimmunity reviews,
