Determination of the organization of proteins and lipids within biological membranes underlies our ability to understand the functions of cell membranes and the cell itself. Such basic knowledge is important to an understanding of any disease at the cellular and molecular level. We will concentrate upon the existence and functional role of associations between membrane proteins. The Ca++ ATPase, the Ca++ pump of mammalian muscle, and bacteriorhodopsin, the bacterial light activated H+ pump, are the two proteins to be studied. In these studies we will further develop and apply new and powerful fluorescence quenching and energy transfer techniques to measurement of the state of self-association of these proteins. We will try to identify the environmental factors which may promote or inhibit oligomer formation, with special emphasis on the role of different phospholipids and cholesterol. By correlation of enzymatic activity and oligomeric state we hope to determine whether oligomers are required for or regulate biological function. Our long term goal is to develop the fluorescence techniques we will use for more general and routine applications. Eventually, we would like to examine the role of membrane receptor aggregation in hormone function and internalization.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM031986-03
Application #
3280456
Study Section
Physical Biochemistry Study Section (PB)
Project Start
1983-04-01
Project End
1986-11-30
Budget Start
1985-04-01
Budget End
1986-11-30
Support Year
3
Fiscal Year
1985
Total Cost
Indirect Cost
Name
State University New York Stony Brook
Department
Type
Schools of Arts and Sciences
DUNS #
804878247
City
Stony Brook
State
NY
Country
United States
Zip Code
11794
Wang, Jie; London, Erwin (2009) The membrane topography of the diphtheria toxin T domain linked to the a chain reveals a transient transmembrane hairpin and potential translocation mechanisms. Biochemistry 48:10446-56
Lai, Bing; Zhao, Gang; London, Erwin (2008) Behavior of the deeply inserted helices in diphtheria toxin T domain: helices 5, 8, and 9 interact strongly and promote pore formation, while helices 6/7 limit pore formation. Biochemistry 47:4565-74
Fujita, Kentaro; Krishnakumar, Shyam S; Franco, David et al. (2007) Membrane topography of the hydrophobic anchor sequence of poliovirus 3A and 3AB proteins and the functional effect of 3A/3AB membrane association upon RNA replication. Biochemistry 46:5185-99
Buchanan, Susan K; Lukacik, Petra; Grizot, Sylvestre et al. (2007) Structure of colicin I receptor bound to the R-domain of colicin Ia: implications for protein import. EMBO J 26:2594-604
White, Dawn; Musse, Abdiwahab A; Wang, Jie et al. (2006) Toward elucidating the membrane topology of helix two of the colicin E1 channel domain. J Biol Chem 281:32375-84
Wu, Zhengyan; Jakes, Karen S; Samelson-Jones, Ben S et al. (2006) Protein translocation by bacterial toxin channels: a comparison of diphtheria toxin and colicin Ia. Biophys J 91:3249-56
Wang, Jie; Rosconi, Michael P; London, Erwin (2006) Topography of the hydrophilic helices of membrane-inserted diphtheria toxin T domain: TH1-TH3 as a hydrophilic tether. Biochemistry 45:8124-34
Zhao, Gang; London, Erwin (2006) An amino acid ""transmembrane tendency"" scale that approaches the theoretical limit to accuracy for prediction of transmembrane helices: relationship to biological hydrophobicity. Protein Sci 15:1987-2001
Musse, Abdiwahab A; Wang, Jie; Deleon, Gladys P et al. (2006) Scanning the membrane-bound conformation of helix 1 in the colicin E1 channel domain by site-directed fluorescence labeling. J Biol Chem 281:885-95
Zhao, Gang; London, Erwin (2005) Behavior of diphtheria toxin T domain containing substitutions that block normal membrane insertion at Pro345 and Leu307: control of deep membrane insertion and coupling between deep insertion of hydrophobic subdomains. Biochemistry 44:4488-98

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