INTERACTIONS BETWEEN H-1 AND CA2-1 IN MYXICOLA AXON

长期目标是更好地了解 细胞内游离钙(钙)i和游离钙的调节 质子，(H)，以及这两个离子之间的相互依赖 浓度。这些离子现在已知或怀疑是 调节或影响多种细胞功能，包括肌肉 收缩、神经分泌、离子通透性、细胞间 电耦合、细胞分裂和分化，以及 新陈代谢。钙的调节机制将在 四个基因座：(A)内质网，(B)质膜，(C) 细胞内钙结合蛋白，以及(D)线粒体。钙 神经内质网的摄取和释放 细胞质将使用一种新的钙电极进行表征 检测NM浓度范围内的游离钙。依赖于ATP 钙的吸收将在线粒体存在的情况下进行研究。 作为ATP、pH和(CA2)的函数的抑制剂。的影响 咖啡因和肌醇磷酸盐对细胞器钙释放的影响 靠近质膜会被比作细胞器 在轴突中心附近。细胞内钙结合蛋白将 要特别重视神经丝的研究。这15万人- 将分离出16万个分子量神经丝蛋白 钙与这些蛋白质的结合将是定量的 在不同pH、离子强度和 温度。使用有限的、特定的蛋白水解性切割和 放射自显影分析，神经丝的部分 包含钙结合部位的分子将被检测。这个 将研究pH对线粒体的影响。vbl.使用 四苯酚膦(TPP)，TPP微电极，以及 含线粒体的轴浆标本，pH值对线粒体的影响 线粒体膜电位将被检测以确定是否 这解释了先前关于pH和钙摄取的观察结果。 利用pH微电极和细胞质的分离样品， 神经细胞质中的“有效”氢离子扩散系数 将被确定，以及固定和流动pH的重要性 将对消散细胞内pH梯度的缓冲液进行评估。

Long-term objectives are to gain a better understanding of the regulation of both intracellular free calcium (Ca2+) i, and free protons, (H+), and the interdependence between these two ion concentrations. These ions are now known or suspected to regulate or influence numberous cell functions, including muscle contraction, neuro-secretion, ion permeability, intercellular electrical coupling, cell division and differentiation, and metabolism. Calcuium regulatory mechanisms will be examined at four loci: (a) endoplasmic reticulum, (b) plasma membrane, (c) intracellular Ca-binding proteins, and (d) mitochondria. Calcium uptake and release from the endoplasmic reticulum of neural cytoplasm iwll be characterized using a new Ca electrode that detects free Ca in the nM concentration range. ATP-dependent Ca uptake will be studied in the presence of mitochondrial inhibitors as a function of ATP, pH, and (cA2+). The effects of caffeine and inositol phosphates on Ca release from organelles close to the plasma membrane will be compared to organelles near the center of the axon. Intracellular Ca-binding proteins will be studied with special emphasis on neurofilaments. The 150,000- 160,000 molecular-weight neurofilament proteins will be isolated and the binding of Ca to these proteins will be quantitiatively examined in solutions of different pH, ionic strength, and temperature. Using limited, specific proteolytic cleavage and autoradiographic analysis, the portions of the neurofilament molecule containg the calcium-binding site will be examined. The influence of pH on mitochondria will be studied. Using tetraphenol phosphonium (TPP+), a TPP+-microelectrode, and samples of axoplasm containing mitochondria, the effect of pH on the mitochondrial membrane potential will be examined to see if this explains a previus observation concerning pH and Ca uptake. Using pH microelectrodes and isolated samples of cytoplasm, the "effective" hydrogen ion diffusion coefficient in neural cytoplasm will be determined, and the importance of fixed and mobile pH buffers in dissipating intracellular pH gradients will be evaluated.