Glycosaminoglycan structures required for strong binding to midkine, a heparin-binding growth factor.
Midkine (MK), a heparin-binding growth factor, binds strongly to oversulfated structures in chondroitin sulfates (CSs) and heparan sulfate. To elucidate the carbohydrate structure actually involved in the strong binding, dissected brains from 13-day mouse embryos were incubated with [14C]-glucosamine. The labeled glycosaminoglycans were fractionated by MK-agarose affinity chromatography to a weakly binding fraction, which was eluted by 0.5 M NaCl, and a strongly binding fraction, which was eluted by higher NaCl concentrations. Among the unsaturated disaccharides released from the strongly binding fraction by chondroitinase ABC, DeltaDi-diSE with 4,6-disulfated N-acetylgalactosamine accounted for 32.3%, whereas its content was lower in the weakly binding fraction. Artificial CS-E structure was formed using N-acetylgalactosamine 4-sulfate 6-O-sulfotransferase purified from squid or recombinant human enzyme. Analysis of the products and their interaction with MK revealed that E units without 3-O-sulfation of glucuronic acid are sufficient for strong binding, provided that they are present as a dense cluster. Among the sulfated disaccharides released by heparitinase digestion, the trisulfated one, DeltaDiHS-triS, was the most abundant in the strongly binding fraction and was lower in the weakly binding fraction. Together with results of previous studies, we concluded that the multivalent trisulfated heparin-like unit is another structure involved in strong binding to MK.
Zou
Peng
P
Department of Biochemistry, Nagoya University School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
Zou
Kun
K
Muramatsu
Hisako
H
Ichihara-Tanaka
Keiko
K
Habuchi
Osami
O
Ohtake
Shiori
S
Ikematsu
Shinya
S
Sakuma
Sadatoshi
S
Muramatsu
Takashi
T
D000818:Animals; D001921:Brain / Q000196:embryology / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D002356:Cartilage / Q000201:enzymology*; D011508:Chondroitin Sulfate Proteoglycans / Q000302:isolation & purification / Q000378:metabolism*; D002846:Chromatography, Affinity; D016207:Cytokines / Q000378:metabolism; D049832:Decapodiformes; D004187:Disaccharides / Q000032:analysis / Q000737:chemistry; D020723:Glucuronic Acid / Q000378:metabolism; D006025:Glycosaminoglycans / Q000737:chemistry / Q000378:metabolism*; D006497:Heparan Sulfate / Q000378:metabolism; D006801:Humans; D000078792:Midkine; D009414:Nerve Growth Factors / Q000378:metabolism; D011133:Polysaccharide-Lyases / Q000378:metabolism; D051381:Rats; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D015238:Sulfotransferases / Q000302:isolation & purification / Q000378:metabolism*
D002352:Carrier Proteins; D011508:Chondroitin Sulfate Proteoglycans; D016207:Cytokines; D004187:Disaccharides; D020723:Glucuronic Acid; D006025:Glycosaminoglycans; D006497:Heparan Sulfate; D000078792:Midkine; D009414:Nerve Growth Factors; D011133:Polysaccharide-Lyases; D011994:Recombinant Proteins; D015238:Sulfotransferases; C416670:N-acetylgalactosamine 4-sulfate 6-O-sulfotransferase; C021349:heparitinsulfate lyase