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Title: Spectral studies of Lanthanide interactions with membrane surfaces

Abstract

We have monitored the interactions of the series of trivalent lanthanide cations with the thylakoid membrane surface of spinach chloroplasts using two complementary spectral techniques. Measurements of the fluorescence emission of the extrinsic probe 2-p-toluidinonaphthalene-6-sulfonate (TNS) and the absorbance of the intrinsic chromophore chlorophyll provide two sensitive means of characterizing the dependence of the cation-membrane interaction on the nature of the cation. In these systems, added lanthanide cations adsorb onto the membrane surface to neutralize exposed segments of membrane-embedded protein complexes. The lanthanide-induced charge neutralization increases the proximity of added TNS anion to the membrane surface as evidenced by variations in the TNS fluorescence level and wavelength of maximum emission. Our results reveal a strong dependence of TNS fluorescence parameters on both lanthanide size and total orbital angular momentum L value. Lanthanides with greater charge density (small size and/or low L value) enhance the TNS fluorescence level to a greater extent. A possible origin for the lanthanide-dependent TNS fluorescence levels is suggested in terms of a heterogeneity in the number and type of TNS binding sites. The data are consistent with the proposal that larger lanthanides with smaller enthalpies of hydration induce more significant membrane appression. 59 refs., 9 figs.,more » 2 tabs.« less

Authors:
; ; ; ; ; ; ;  [1]
  1. Harvey Mudd College, Claremont, CA (United States)
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
35453
Resource Type:
Journal Article
Journal Name:
Journal of Physical Chemistry
Additional Journal Information:
Journal Volume: 99; Journal Issue: 12; Other Information: PBD: 23 Mar 1995
Country of Publication:
United States
Language:
English
Subject:
40 CHEMISTRY; 55 BIOLOGY AND MEDICINE, BASIC STUDIES; CATIONS; INTERACTIONS; PROBES; EMISSION SPECTRA; FLUORESCENCE; THYLAKOID MEMBRANE PROTEINS; CHLOROPLASTS; BINDING ENERGY; CHLOROPHYLL; THULIUM IONS; ABSORPTION SPECTRA; RARE EARTH COMPOUNDS; PHOTOSYNTHETIC MEMBRANES

Citation Formats

Karukstis, K K, Kao, M Y, Savin, D A, Bittker, R A, Kaphengst, K J, Emetarom, C M, Naito, N R, and Takamoto, D Y. Spectral studies of Lanthanide interactions with membrane surfaces. United States: N. p., 1995. Web. doi:10.1021/j100012a067.
Karukstis, K K, Kao, M Y, Savin, D A, Bittker, R A, Kaphengst, K J, Emetarom, C M, Naito, N R, & Takamoto, D Y. Spectral studies of Lanthanide interactions with membrane surfaces. United States. https://doi.org/10.1021/j100012a067
Karukstis, K K, Kao, M Y, Savin, D A, Bittker, R A, Kaphengst, K J, Emetarom, C M, Naito, N R, and Takamoto, D Y. 1995. "Spectral studies of Lanthanide interactions with membrane surfaces". United States. https://doi.org/10.1021/j100012a067.
@article{osti_35453,
title = {Spectral studies of Lanthanide interactions with membrane surfaces},
author = {Karukstis, K K and Kao, M Y and Savin, D A and Bittker, R A and Kaphengst, K J and Emetarom, C M and Naito, N R and Takamoto, D Y},
abstractNote = {We have monitored the interactions of the series of trivalent lanthanide cations with the thylakoid membrane surface of spinach chloroplasts using two complementary spectral techniques. Measurements of the fluorescence emission of the extrinsic probe 2-p-toluidinonaphthalene-6-sulfonate (TNS) and the absorbance of the intrinsic chromophore chlorophyll provide two sensitive means of characterizing the dependence of the cation-membrane interaction on the nature of the cation. In these systems, added lanthanide cations adsorb onto the membrane surface to neutralize exposed segments of membrane-embedded protein complexes. The lanthanide-induced charge neutralization increases the proximity of added TNS anion to the membrane surface as evidenced by variations in the TNS fluorescence level and wavelength of maximum emission. Our results reveal a strong dependence of TNS fluorescence parameters on both lanthanide size and total orbital angular momentum L value. Lanthanides with greater charge density (small size and/or low L value) enhance the TNS fluorescence level to a greater extent. A possible origin for the lanthanide-dependent TNS fluorescence levels is suggested in terms of a heterogeneity in the number and type of TNS binding sites. The data are consistent with the proposal that larger lanthanides with smaller enthalpies of hydration induce more significant membrane appression. 59 refs., 9 figs., 2 tabs.},
doi = {10.1021/j100012a067},
url = {https://www.osti.gov/biblio/35453}, journal = {Journal of Physical Chemistry},
number = 12,
volume = 99,
place = {United States},
year = {Thu Mar 23 00:00:00 EST 1995},
month = {Thu Mar 23 00:00:00 EST 1995}
}