{"title":"水合紫色膜的介电色散和质子传导。","authors":"I Kovács, G Váró","doi":"","DOIUrl":null,"url":null,"abstract":"<p><p>Dielectric dispersion effects were studied in purple membranes of different hydration levels. The capacitance and conductivity were measured over the frequency range of 10(2) Hz to 10(5) Hz. With increase in the hydration level, the conductivity increases sharply above the critical hydration of hc = 0.06 g H2O/g protein. This critical hydration is close to the extent of the first continuous strongly bound water layer and is interpreted as the threshold for percolative proton transfer. The capacitance increases continuously with increasing hydration and a larger increase above the water content of 0.1 g H2O/g protein can be seen only at low frequencies. Maxwell-Wagner relaxation also appears above this hydration, showing the presence of a bulk water phase.</p>","PeriodicalId":77479,"journal":{"name":"Acta biochimica et biophysica Hungarica","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"1988-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Dielectric dispersion and protonic conduction in hydrated purple membrane.\",\"authors\":\"I Kovács, G Váró\",\"doi\":\"\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>Dielectric dispersion effects were studied in purple membranes of different hydration levels. The capacitance and conductivity were measured over the frequency range of 10(2) Hz to 10(5) Hz. With increase in the hydration level, the conductivity increases sharply above the critical hydration of hc = 0.06 g H2O/g protein. This critical hydration is close to the extent of the first continuous strongly bound water layer and is interpreted as the threshold for percolative proton transfer. The capacitance increases continuously with increasing hydration and a larger increase above the water content of 0.1 g H2O/g protein can be seen only at low frequencies. Maxwell-Wagner relaxation also appears above this hydration, showing the presence of a bulk water phase.</p>\",\"PeriodicalId\":77479,\"journal\":{\"name\":\"Acta biochimica et biophysica Hungarica\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"1988-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Acta biochimica et biophysica Hungarica\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Acta biochimica et biophysica Hungarica","FirstCategoryId":"1085","ListUrlMain":"","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
摘要
研究了不同水化水平紫色膜的介电色散效应。在10(2)Hz至10(5)Hz的频率范围内测量电容和电导率。随着水化水平的增加,电导率在hc = 0.06 g H2O/g protein的临界水化水平以上急剧增加。这一临界水合作用接近第一连续强结合水层的程度,并被解释为渗透质子转移的阈值。电容随水化程度的增加而持续增加,只有在低频时,在0.1 g H2O/g蛋白质的含水量以上才有较大的增加。麦克斯韦-瓦格纳弛豫也出现在水合作用之上,表明存在大量的水相。
Dielectric dispersion and protonic conduction in hydrated purple membrane.
Dielectric dispersion effects were studied in purple membranes of different hydration levels. The capacitance and conductivity were measured over the frequency range of 10(2) Hz to 10(5) Hz. With increase in the hydration level, the conductivity increases sharply above the critical hydration of hc = 0.06 g H2O/g protein. This critical hydration is close to the extent of the first continuous strongly bound water layer and is interpreted as the threshold for percolative proton transfer. The capacitance increases continuously with increasing hydration and a larger increase above the water content of 0.1 g H2O/g protein can be seen only at low frequencies. Maxwell-Wagner relaxation also appears above this hydration, showing the presence of a bulk water phase.