TY - JOUR
T1 - Human ovarian cancer, lymphoma spleen, and bovine milk GlcNAc:β1,4Gal/GalNAc transferases
T2 - Two molecular species in ovarian tumor and induction of GalNAcβ1,4Glc synthesis by α-lactalbumin
AU - Chandrasekaran, E. V.
AU - Chawda, Ram
AU - Piskorz, Conrad
AU - Locke, Robert D.
AU - Ta, Alyssa
AU - Sharad, Ghamande
AU - Odunsi, Kunle
AU - Lele, Shashikant
AU - Matta, Khushi L.
N1 - Funding Information:
This work was supported by NIH grant No. CA35329 and in part by grant No. CA16056.
PY - 2001/8/23
Y1 - 2001/8/23
N2 - Affinity Gel-UDP was utilized to purify GlcNAc:β1,4Gal/GalNAc transferases (Ts) from human lymphoma spleen, ovarian tumor, and ovarian cancer sera. Mn2+ was found to be an absolute requirement for activity. Two molecular species containing both β1,4Gal/GalNAc-T activities were discernible when the purified ovarian tumor microsomal enzyme was subjected to Sephacryl S-100 HR column chromatography as well as native polyacylamide gel-electrophoresis. Acceptor specificity studies of the affinity-purified lymphoma spleen and ovarian tumor microsomal enzymes and the conventionally purified, as well as the cloned, bovine milk GlcNAc:β1,4Gal-Ts using a number of synthetic acceptors showed that the β(1,6)-linked GlcNAc moiety to α-GalNAc was the most efficient acceptor. As compared to the purified milk enzyme, the recombinant form exhibited sixfold GlcNAc:β1,4 GalNAc-T activity and up to eightfold GlcNAc6SO3β-:β1,4Gal-T activity. Further, the recombinant enzyme catalyzed the transfer of GalNAc to the terminal β-linked GlcNAc6SO3 moiety. Alpha-lactalbumin (α-LA) inhibited up to 85%, the transfer of Gal to the GlcNAc moiety linked either to Man or GlcNAc. On the contrary, α-LA had no significant influence on the transfer of GalNAc to the above acceptors. α-LA had no appreciable effect on the recombinant enzyme, except for the transfer of Gal or GalNAc to Glc. Both α- and β-glucosides, as well as α-N-acetylglucosaminide, did not serve as acceptors.
AB - Affinity Gel-UDP was utilized to purify GlcNAc:β1,4Gal/GalNAc transferases (Ts) from human lymphoma spleen, ovarian tumor, and ovarian cancer sera. Mn2+ was found to be an absolute requirement for activity. Two molecular species containing both β1,4Gal/GalNAc-T activities were discernible when the purified ovarian tumor microsomal enzyme was subjected to Sephacryl S-100 HR column chromatography as well as native polyacylamide gel-electrophoresis. Acceptor specificity studies of the affinity-purified lymphoma spleen and ovarian tumor microsomal enzymes and the conventionally purified, as well as the cloned, bovine milk GlcNAc:β1,4Gal-Ts using a number of synthetic acceptors showed that the β(1,6)-linked GlcNAc moiety to α-GalNAc was the most efficient acceptor. As compared to the purified milk enzyme, the recombinant form exhibited sixfold GlcNAc:β1,4 GalNAc-T activity and up to eightfold GlcNAc6SO3β-:β1,4Gal-T activity. Further, the recombinant enzyme catalyzed the transfer of GalNAc to the terminal β-linked GlcNAc6SO3 moiety. Alpha-lactalbumin (α-LA) inhibited up to 85%, the transfer of Gal to the GlcNAc moiety linked either to Man or GlcNAc. On the contrary, α-LA had no significant influence on the transfer of GalNAc to the above acceptors. α-LA had no appreciable effect on the recombinant enzyme, except for the transfer of Gal or GalNAc to Glc. Both α- and β-glucosides, as well as α-N-acetylglucosaminide, did not serve as acceptors.
KW - Bovine milk
KW - Cancer sera
KW - GlcNAc:β1,4Gal/GalNAc transferases
KW - Human ovarian tumor
KW - Kinetic properties
KW - Lymphoma-spleen
KW - Specificities
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UR - http://www.scopus.com/inward/citedby.url?scp=0035940045&partnerID=8YFLogxK
U2 - 10.1016/S0008-6215(01)00150-1
DO - 10.1016/S0008-6215(01)00150-1
M3 - Article
C2 - 11502266
AN - SCOPUS:0035940045
SN - 0008-6215
VL - 334
SP - 105
EP - 118
JO - Carbohydrate Research
JF - Carbohydrate Research
IS - 2
ER -