NEW METABOLITES AND PATHWAYS IN THE MAMMALIAN LENS

我们鉴定了一种新的磷酸单酯果糖3-磷酸（Fru-3-P） 在糖尿病大鼠透镜中，并显示它是一种有效的交联剂， 体外晶体蛋白。 我们还证明了Fru-3-P分解 3-脱氧葡萄糖酮（3dG）是一种有效的蛋白质交联剂，并已显示 这种二羰基存在于糖尿病患者的透镜中。 本研究 我们建议进一步评估Fru-3-P在 糖尿病大鼠透镜通过鉴定其他可能的糖化剂， 组织，并评价其相对于Fru-3-P的糖化潜力。 Fru-3-P原来是占主导地位的糖化剂，如由 初步数据，我们将随后确定动力学参数 Fru-3-P和3dG介导的大鼠晶体蛋白糖基化及对晶体蛋白糖基化的影响 测定糖尿病患者中由这些化合物介导的糖化量 大鼠体内透镜。 由于果糖3-磷酸是由一种新的酶从果糖合成的， 果糖-3-磷酸激酶，我们将纯化这种酶，并确定其 分子身份以及其动力学和机械性质。

We have identified a novel phosphomonoester fructose 3-phosphate (Fru-3-P) in the diabetic rat lens and shown it to be a potent crosslinking agent of crystallins in vitro. We have also demonstrated that Fru-3-P decomposes to 3-deoxyglucosone (3dG) a potent protein crosslinker, and have shown that this dicarbonyl is present in the diabetic lens. In this research program we propose to further assess the importance of Fru-3-P in the diabetic rat lens by identifying other possible glycating agents in this tissue and to evaluate their glycation potential relative to Fru-3-P. If Fru-3-P turns out to be the dominant glycating agent, as suggested by preliminary data, we will subsequently determine the kinetic parameters of Fru-3-P and 3dG mediated glycation of rat crystallins in vitro and determine the amount glycation mediated by these compounds in the diabetic rat lens in vivo. Since fructose 3-phosphate is synthesized from fructose by a novel enzyme fructose-3-phosphokinase, we will purify this enzyme and determine its molecular identity as well as its kinetic and mechanistic properties.