BIOCHEMISTRY OF GLYCOLIPIDS IN GASTRIC SECRETION

本研究的具体目标是：确定 和分离的未降解粘液糖蛋白中的脂质组成 从胃粘液;建立甘油糖脂的要求， 与粘液糖蛋白相互作用， 相互作用涉及蛋白质或碳水化合物成分的 糖蛋白;提供有关脂质拓扑结构的信息 在未降解的胃粘液糖蛋白聚合物中;以确定 甘油糖脂是否保护粘液糖蛋白聚合物免受 胃蛋白酶降解;以确定脂质对流变学的影响 粘液糖蛋白的性质，和J来评估粘液的作用 脂质在H+阻滞过程中的胃粘液;以确定 是否参与生物合成的酶的活性 胃疾病患者胃粘膜中的甘油糖脂 不同于普通人。 未降解的粘液糖蛋白，分离 用平衡离心法从猪、狗和大鼠胃粘液中分离得到 CsCl密度梯度，将用于研究的内容和组成， 脂质。 未降解的粘液糖蛋白解离成中心糖蛋白， 蛋白质组分和还原糖蛋白单体将进行 通过二硫键的还原裂解。 脂质对 粘液糖蛋白的消化性消化将通过 三硝基苯化法 粘度测量及粘度计的研究 脂质在胃粘液阻滞H+扩散中的作用， 对完整的和脱脂的粘液和糖蛋白进行。 人类 胃粘膜活检标本将用于研究 参与甘油糖脂生物合成的酶。

The specific goals of the proposed research are: to detemine the content and composition of lipids in the undegraded mucus glycoprotein isolated from gastric mucus; to establish the requirements of glyceroglucolipids for for interacting with mucus glycoprotein, and to determine whether this interaction involves the protein or carbohydrate component of the glycoprotein; to provide the information as to the topography of lipids within the undegraded gastric mucus glycoprotein polymer; to determine whether glyceroglucolipids protect the mucus glycoprotein polymer from the degradation by pepsin; to determine the effect of lipids on the rheological properties of mucus glycoprotein, and J to evaluate the role of mucus lipids in the process of H+ retardation by gastric mucus; to determine whether activities of enzymes involved in the biosynthesis of glyceroglucolipids in gastric mucosa of patients with gastric diseases differ from that of normals. The undegraded mucus glycoproteins, isolated from pig, dog and rat gastric mucus by the equilibrium centrifugation in CsCl density gradient, will be used to study the content and composition of lipids. Dissociation of the undegraded mucus glycoproteins into a central protein component and the reduced glycoprotein monomers will be performed by the reductive cleavage of dissulfide bridges. The effect of lipids on the peptic digestion of mucus glycoprotein will be measured by the trinitrophenylation method. Viscosity measurements and the study on the role of lipids in the retardation of H+ diffusion by gastric mucus will be performed on the intact and delipidated mucus and glycoprotein. Human gastric mucosal biopsy specimens will be used to study the activities of enzymes involved in the biosynthesis of glyceroglucolipids.