LIPID CONTROL OF MEMBRANE PROTEIN ORGANIZATION

  • Mendelsohn, Richard (PI)
  • Mendelsohn, Richard (PI)
  • Mendelsohn, Richard (PI)

Project Details

Description

The long term objective of this work is to determine the
conformational changes that occur in proteins and phospholipids
upon their mutual interaction. The principles involved will
provide a basis for understanding the molecular organization of
biological membranes and how the organization may be altered
during pathological conditions. Three specific aims will be addressed to achieve this objective: (1) To determine whether integral membrane proteins
preferentially partition into regions of specific chemical structure
or physical order in complex phospholipid environments, and to
determine the relationship of any observed partitioning to the
function of membrane-bound enzymes. (2) To determine the site and magnitude of the interactions
produced by membrane proteins and membrane-active peptides on
phospholipid molecules. (3) To determine changes in conformation and orientational order
that occur in both the phospholipid and protein components upon
their mutual interaction in model vesicle and planar bilayer
systems, and in a reasonably simple native preparation (lung
surfactant) to be studied in vitro. The main physical method to be employed to study in non-
perturbative fashion both lipid configuration and protein
secondary structure is Fourier Transform Infrared (FT-IR)
spectroscopy. The thermodynamics of lipid-protein interactions is
evaluated with high sensitivity Differential Scanning Calorimetry
(DSC). To achieve Aim 1, CaATPase from rabbit sarcoplasmic reticulum
is isolated, purified, and reconstituted into phospholipid
environments selected to mimic those in vivo. The miscibility and
partitioning characteristics of the system are determined with
FT-IR and DSC. Aim 2 is achieved by reconstitution of the
desired membrane protein or peptide with phospholipids
deuterated at specific positions in the acyl chains. Perturbations
at the specific site in the latter will be monitored with attenuated
total reflectance spectroscopy. Aim 3 is addressed by
determination of the type and geometric orientation of protein or
peptide secondary structure via the conformation-sensitive Amide
I or II spectral regions. The organizational principles deduced through the above
experiments will be extended to a simple native tissue, lung
surfactant, to be studied in vitro. The molecular basis of the
stability and spreading of surfactant at the air-water interface
will be probed.
StatusFinished
Effective start/end date12/31/891/31/09

Funding

  • National Institute of General Medical Sciences
  • National Institute of General Medical Sciences
  • National Institute of General Medical Sciences: $238,135.00
  • National Institute of General Medical Sciences
  • National Institute of General Medical Sciences: $287,513.00
  • National Institute of General Medical Sciences
  • National Institute of General Medical Sciences
  • National Institute of General Medical Sciences: $245,036.00
  • National Institute of General Medical Sciences
  • National Institute of General Medical Sciences: $303,225.00
  • National Institute of General Medical Sciences
  • National Institute of General Medical Sciences
  • National Institute of General Medical Sciences
  • National Institute of General Medical Sciences: $296,100.00
  • National Institute of General Medical Sciences
  • National Institute of General Medical Sciences
  • National Institute of General Medical Sciences
  • National Institute of General Medical Sciences
  • National Institute of General Medical Sciences: $321,067.00
  • National Institute of General Medical Sciences: $231,435.00
  • National Institute of General Medical Sciences: $315,790.00
  • National Institute of General Medical Sciences

ASJC

  • Medicine(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Structural Biology
  • Cell Biology

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