9710354 Odde This proposal brings a quantitative, engineering perspective to the study of the chemical and mechanical properties of microtubules (MTs), tubular protein filaments found in most animal cellular cytoplasm. The three aims of the proposed study are: The digital image analysis of the dynamics of MTs at the leading edge of newt lung cells and fibroblasts. This study will quantitatively measure the strain within the cell by direct observation of the dynamics and bending of the MTs. The thermodynamics of MT assembly and disassembly will be studied. The hypothesis is that energy is stored as strain in the MT lattice. Specific MT associated proteins (MAPs) will be used to disrupt the microtubules and the energy release will be measured by calorimetry. The relationship of MT to MAP binding on the strain will be studied. The activity of the MT severing enzyme, katanin, will be measured for both strained and unstrained microtubules. Katanin may be a key regulator of MT turnover in-vivo. ***
