Changes in the elastic properties of cholinergic synaptic vesicles as measured by atomic force microscopy.

Cholinergic synaptic vesicles from Torpedo californica have been probed with the atomic force microscope in aqueous buffers to map and measure their elastic properties. Elastic properties were mapped with a new atomic force microscope technique known as force mapping. Force mapping of vesicles showed that the centers of the vesicles are harder or stiffer than the peripheral areas in the three buffers that were investigated. These were an isoosmotic buffer, a hypoosmotic buffer, and an isoosmotic buffer with 5 mM CaCl2 added. The hardness of the vesicular centers was quantified by calculation of the elastic modulus. Elastic moduli were in the range of 2-13 x 10(5) Pa. Vesicular centers were hardest in calcium-containing buffer and softest in isoosmotic buffer. Hypotheses are presented for the composition and function of the hard centers.

[1]  S. Parsons,et al.  Purification of active synaptic vesicles from the electric organ of Torpedo californica and comparison to reserve vesicles. , 1996, Biochimica et biophysica acta.

[2]  M. Radmacher,et al.  Imaging soft samples with the atomic force microscope: gelatin in water and propanol. , 1995, Biophysical journal.

[3]  R. Scheller,et al.  Synaptic vesicle biogenesis, docking, and fusion: a molecular description. , 1996, Physiological reviews.

[4]  H. Hansma,et al.  Biomolecular imaging with the atomic force microscope. , 1994, Annual review of biophysics and biomolecular structure.

[5]  P. Haydon,et al.  Actin filament dynamics in living glial cells imaged by atomic force microscopy. , 1992, Science.

[6]  H. Hansma.  Atomic force microscopy of biomolecules , 1996 .

[7]  C. Bustamante,et al.  Visualizing protein-nucleic acid interactions on a large scale with the scanning force microscope. , 1996, Annual review of biophysics and biomolecular structure.

[8]  A. Engel,et al.  Native Escherichia coli OmpF porin surfaces probed by atomic force microscopy. , 1995, Science.

[9]  S. Carlson,et al.  The SV2 Protein of Synaptic Vesicles Is a Keratan Sulfate Proteoglycan , 1993, Journal of neurochemistry.

[10]  A. Rephaeli,et al.  Calmodulin stimulation of 45Ca2+ transport and protein phosphorylation in cholinergic synaptic vesicles. , 1982, Proceedings of the National Academy of Sciences of the United States of America.

[11]  H. Hansma,et al.  Applications for atomic force microscopy of DNA. , 1995, Biophysical journal.

[12]  Yves Engelborghs,et al.  Dynamical and mechanical study of immobilized microtubules with atomic force microscopy , 1996 .

[13]  Gus Gurley,et al.  Short cantilevers for atomic force microscopy , 1996 .

[14]  R. Lal,et al.  Dynamic micromechanical properties of cultured rat atrial myocytes measured by atomic force microscopy. , 1995, The American journal of physiology.