Poly-3-Hydroxybutyrate/Polyphosphate Ion Channels

;​R o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o4 @ +, -。/ 0 1 2 3 4 5 F Microsoft Word 6.0 Document MSWordDoc。6;​聚羟基丁酸酯和聚磷酸盐是存在于所有生物细胞中的聚合物，但它们的功能在很大程度上是未知的。本研究者从细菌膜中分离出了一个由聚羟基丁酸盐和聚磷酸盐组成的离子通道。这些聚合物结合形成钙选择性离子通道，其许多特性与植物和动物细胞膜上发现的蛋白钙通道相同。聚羟基丁酸盐和聚磷酸盐形成离子通道的能力来自于聚羟基丁酸盐溶解盐的能力，以及聚磷酸盐结合某些阳离子的能力。聚磷酸盐的离子选择性使其在水软化中得到应用，而聚羟基丁酸盐的溶剂性质与锂电池中使用的聚醚非常相似，这表明聚羟基丁酸盐可以用来制备离子导电材料。本研究将测定温度、pH和盐对从大肠杆菌中提取的多羟基丁酸盐/多磷酸盐离子通道的电导率和选择性的影响，以及由其组分重组的配合物。这些复合物将被纳入平面脂质双分子层，并使用电压箝位技术进行研究。计算机分子力学和分子动力学计算将确定通道复合物中聚合物最可能的构象，并阐明阻塞机制。这些聚合物在通道配合物中的研究将为生物离子通道和体相聚合物电解质中的离子传导机制提供新的见解，并在材料科学中提出新的应用。*** ;Oh +' 0 $ H l D H R:\WWUSER\TEMPLATE\NORMAL。点 文摘 芭芭拉Zain 芭芭拉Zain @ q S u m m r f y我n o r m t I o n ( *1 @ @ ıo9 @ f# Microsoft Word 6.0;e = e l l l l l l l l D 1 # & & # 4 D l D l l聚羟基丁酸酯和聚磷酸盐是存在于所有生物细胞中的聚合物，但它们的功能在很大程度上是未知的。本研究者从细菌膜中分离出了一个由聚羟基丁酸盐和聚磷酸盐组成的离子通道。这些聚合物结合形成钙选择性离子通道，其许多特性与植物和动物细胞膜上发现的蛋白钙通道相同。聚羟基丁酸盐和聚磷酸盐形成离子通道的能力来自于聚羟基丁酸盐溶解盐的能力，以及聚磷酸盐结合某些阳离子的能力。聚磷酸盐的离子选择性使其在水软化中得到应用，而聚羟基丁酸盐的溶剂性质与锂电池中使用的聚醚非常相似，这表明聚羟基丁酸盐可以用来制备离子导电材料。本文研究了温度、pH和盐对多羟基化合物电导率和选择性的影响

; R o o t E n t r y F o9 C o m p O b j b W o r d D o c u m e n t O b j e c t P o o l o9 o9 4 @ + , - . / 0 1 2 3 4 5 F Microsoft Word 6.0 Document MSWordDoc Word.Document.6 ; Abstract 9507282 Reusch Polyhydroxybutyrate and polyphosphate are polymers found in all biological cells, yet their functions are largely unknown. This investigator has isolated an ion channel from bacterial membranes which is composed of polyhydroxybutyrate and polyphosphate. The polymers combine to form a calcium-selective ion channel with many of the same properties as the protein calcium channels found in plant and animal cell membranes. The capacity of polyhydroxybutryate and polyphosphate to form ion channels derives from the ability of the polyhydroxybutryate to dissolve salts, and that of polyphosphate to bind some cations more strongly than others. The ion-selective properties of polyphosphates have led to their use in water-softening, and the solvent properties of polyhydroxybutyrate are very similar to those of the polyethers used in lithium batteries, suggesting that polyhydroxybutryate can be used to prepare ion-conducting materials. In this research the effects of temperature, pH and salts on the conductance and selectivity of the polyhydroxybutryate/polyphosphate ion channel s extracted from E. coli as well as complexes reconstituted from their components uill be determined. These complexes will be incorporated into planar lipid bilayers and studied with voltage clamp techniques. Computer molecular mechanics and molecular dynamics computations will determine the most likely conformations of the polymers in the channel complexes and elucidate blocking mechanisms. %%% These studies on these polymers in channel complexes will provide new insights into the mechanisms of ion-conduction in biological ion channels and bulk phase polymer electrolytes, and suggest new applications in material science. *** ; Oh +' 0 $ H l D h R:\WWUSER\TEMPLATE\NORMAL.DOT Abstract Barbara Zain Barbara Zain @ q S u m m a r y I n f o r m a t i o n ( * 1 @ @ ıo9 @ F # Microsoft Word 6.0 2 ; e = e l l l l l l l D 1 # & u T 4 D l D l l l l l l l l 7 Abstract 9507282 Reusch Polyhydroxybutyrate and polyphosphate are polymers found in all biological cells, yet their functions are largely unknown. This investigator has isolated an ion channel from bacterial membranes which is composed of polyhydroxybutyrate and polyphosphate. The polymers combine to form a calcium-selective ion channel with many of the same properties as the protein calcium channels found in plant and animal cell membranes. The capacity of polyhydroxybutryate and polyphosphate to form ion channels derives from the ability of the polyhydroxybutryate to dissolve salts, and that of polyphosphate to bind some cations more strongly than others. The ion-selective properties of polyphosphates have led to their use in water-softening, and the solvent properties of polyhydroxybutyrate are very similar to those of the polyethers used in lithium batteries, suggesting that polyhydroxybutryate can be used to prepare ion-conducting materials. In this research the effects of temperature, pH and salts on the conductance and selectivity of the polyhydroxybut