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，并定位在含有激素的 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），而在肾上腺中， 称为嗜铬粒蛋白A（ChA）。 由于这种分泌物 蛋白质伴随着这两种组织的激素分泌， 有人认为，这可能是一个共同的特点，所有 内分泌组织 我们计划通过检查 垂体、胰腺和甲状腺，沿着肾上腺， 甲状旁腺组织下的各种分泌和非分泌 条件以确定SP-I/Ch A蛋白是否与 激素. 这些研究将使用新鲜牛组织进行 在4-5小时的时间内将切片置于灌注装置中， 通过放射免疫测定法分析灌注液中SP-1/Ch A， 激素. 因为我们已经建立的结构信息 SP-Ⅰ和Ch A的同源性几乎相同 我们还建议从垂体中分离SP-I/ChA， 这样我们就可以确定 在这些组织中发生的是化学上类似于SP-I/Ch A 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 和胰蛋白质，然后通过HPLC分离胰蛋白质， 用于与获得的类似摘要的地图进行比较的图表 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，我们将描述穷人的特点。 了解SP-1/Ch A的Ca++依赖性蛋白水解， 发生在破碎的细胞制剂中。 这种特性将是 （a）确定具体要求， 蛋白水解并检查所得产物; B）测定 无论这种蛋白水解是否发生在细胞内， c）确定SP-I/Ch的形式是否 与蛋白水解有关 产品. 这些研究（B & c）将使用分散的 甲状旁腺细胞和放射性氨基酸标记SP-I 沿着用凝胶电泳和HPLC分离进行分析 SP-I的形式。 嗜铬颗粒的分离裂解物将 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.