Boskey A L, Dick B L
Department of Ultrastructural Biochemistry, Hospital for Special Surgery, New York, NY 10021.
Matrix. 1991 Dec;11(6):442-6. doi: 10.1016/s0934-8832(11)80198-8.
The interaction of hyaluronan (Mr range 80-120 x 10(4)) with poorly crystalline hydroxyapatite, such as is found in calcified cartilage and bone, was studied to challenge the hypothesis that free hyaluronan found in proteoglycan aggregate preparations could affect in vitro mineralization. Using a Langmuir adsorption isotherm, based on uronic acid content, hyaluronan was found to bind to hydroxyapatite with an affinity K of 0.12 ml/microgram uronate and N = 6.8 micrograms uronate/m2 hydroxyapatite binding sites. This is contrasted with K = .047 ml/microgram uronate and N = 9.0 micrograms uronate/m2 for a bovine nasal proteoglycan monomer preparation. Although the proteoglycan monomer and aggregate preparations have been reported to inhibit hydroxyapatite growth at concentrations of 1 mg/ml, using solution concentrations of 0, 0.01, 0.1 and 1 mg/ml hyaluronan there were no detectable alterations in the rate of seeded hydroxyapatite growth and proliferation. These data indicate that although in vitro hyaluronan may bind with weak affinity to hydroxyapatite, this interaction does not affect mineral growth, and the presence of hyaluronan would not contribute to the increased inhibitory potential of cartilage proteoglycan aggregate relative to monomer preparations.
研究了透明质酸（分子量范围80 - 120×10⁴）与结晶度差的羟基磷灰石（如在钙化软骨和骨中发现的）之间的相互作用，以验证蛋白聚糖聚集体制剂中发现的游离透明质酸可能影响体外矿化这一假说。基于糖醛酸含量，利用朗缪尔吸附等温线，发现透明质酸以亲和力K = 0.12 ml/μg糖醛酸和N = 6.8 μg糖醛酸/m²羟基磷灰石结合位点与羟基磷灰石结合。这与牛鼻蛋白聚糖单体制剂的K = 0.047 ml/μg糖醛酸和N = 9.0 μg糖醛酸/m²形成对比。尽管据报道蛋白聚糖单体和聚集体制剂在浓度为1 mg/ml时可抑制羟基磷灰石生长，但使用0、0.01、0.1和1 mg/ml透明质酸的溶液浓度时，接种的羟基磷灰石生长和增殖速率没有可检测到的变化。这些数据表明，虽然体外透明质酸可能以弱亲和力与羟基磷灰石结合，但这种相互作用不影响矿物质生长，并且透明质酸的存在不会导致软骨蛋白聚糖聚集体相对于单体制剂的抑制潜力增加。
