PARATHYROID SECRETORY PROTEIN IN KEY ENDOCRINE GLANDS

拟议工作的长期目标是发现 一类蛋白质的生理功能 内分泌组织并位于含有激素的范围内 这些组织的细胞。 在甲状旁腺中，这种蛋白质是 称为分泌蛋白-I (SP-I)，在肾上腺中它是 称为嗜铬粒蛋白 A (Ch A)。 自从分泌了这个 蛋白质伴随着这两种组织的激素分泌 有人认为这可能是所有人的共同特征 内分泌组织。 我们计划通过检查来检验这个假设 垂体、胰腺和甲状腺，以及肾上腺和 甲状旁腺组织有多种分泌性和非分泌性 确定 SP-I/Ch A 蛋白是否分泌的条件 激素。 这些研究将使用新鲜牛组织进行 在灌注装置中切片 4-5 小时， 通过放射免疫分析法分析灌注液中的 SP-1/Ch A 和每个 激素。 由于我们已经建立了结构信息 SP-I 和 Ch A 表明它们是几乎相同的同源物 我们还建议将 SP-I/Ch A 与垂体分离， 胰腺，以便我们可以确定该物种是否 这些组织中发生的化学成分与 SP-I/Ch A 相似 甲状旁腺/肾上腺。 这些比较将由 对垂体进行酶促和化学消化 和胰蛋白，然后通过 HPLC 分离 摘要用于与获得的类似摘要的图进行比较 来自甲状旁腺和肾上腺蛋白。 此外，我们将 对分离的多肽进行氨基酸分析 进一步比较。 最后，我们将描述较差的特征 了解 SP-I/Ch A 的 Ca 依赖性蛋白水解作用 发生在破碎的细胞制剂中。 这样的表征将是 a) 建立具体要求 蛋白水解并检查所得产物； b) 确定 这种蛋白水解作用是否发生在细胞内以产生 类似产品； c) 确定 SP-I/Ch 的形式是否 分泌的 A 与蛋白水解有任何关系 产品。 这些研究（b 和 c）将使用分散的 甲状旁腺细胞和放射性氨基酸来标记 SP-I 结合凝胶电泳和 HPLC 分离进行分析 SP-I的形式。 嗜铬颗粒的分离裂解物将是 用于 a 部分。

The long-term objective of the proposed work is to discover the physiological function of a class of proteins which occur in endocrine tissues and are localized within hormone containing cells of these tissues. In the parathyroid gland this protein is called secretory protein-I (SP-I) while in the adrenal gland it is referred to as chromogranin A (Ch A). Since secretion of this protein accompanies hormone secretion from these 2 tissues it has been suggested that this may be a common feature of all endocrine tissues. We plan to test this hypothesis by examining pituitary, pancreas, and thyroid, along with adrenal and parathyroid tissues under a variety of secretory and non-secretory conditions to determine if an SP-I/Ch A protein is secreted with hormone. These studies will be done with fresh bovine tissue slices in a perifusion apparatus over a 4-5 hour period and perifusate analyzed by radioimmunoassay for SP-1/Ch A and each hormone. Since the structural information we have established for SP-I and Ch A indicate they are nearly identical homologues we also propose to isolate the SP-I/Ch A from pituitary and pancreas so that we can determine whether or not the species occurring in these tissues is chemically similar to the SP-I/Ch A of parathyroid/adrenal. These comparisons will be made by performing enzymatic and chemical digestions of the pituitary and pancreatic proteins followed by HPLC separation of the digests for comparison to the maps of similar digest obtained from the parathyroid and adrenal proteins. In addition, we will perform amino acid analysis of the separated polypeptides for further comparison. Finally, we will characterize the poorly understood Ca++ -dependent proteolysis of SP-I/Ch A which occurs in broken cell preparations. Such characterization will be approached by a) establishing the specific requirements of the proteolysis and examining the resulting products; b) determining whether or not such proteolysis occurs intracellularly to produce similar products; c) determining whether or not forms of SP-I/Ch A which are secreted bear any relationship to proteolytic products. These studies (b & c) will be conducted using dispersed parathyroid cells and radioactive amino acids to label the SP-I along with gel electrophoresis and HPLC separation to analyze forms of SP-I. Isolated lysates of chromaffin granules will be utilized for part a.