The majority of chloroplast proteins are nuclear encoded and transcribed on cytosolic ribosomes, and therefore must be post-translationally imported into the chloroplast. Preproteins are directed to the chloroplast via a cleavable Nterminal extension known as a transit peptide. This transport is mediated by the Toc and Tic complexes (Translocon at the Outer/Inner Chloroplast envelope membrane), functioning in tandem to transport preproteins into chloroplasts relying on the hydrolysis of ATP and GTP. The Toc complex is composed of the β-barrel channel protein Toc75 and the homologous GTPase receptors Toc34 and Toc159. GTP hydrolysis is necessary for the formation of the early import intermediate, in which the transit peptide is inserted into the Toc channel, but the presence of internal ATP is the only energetic requirement for the later stages of translocation to occur, mediated by the stromal motor complex with an Hsp100 isoform hydrolyzing stromal ATP. The purpose of the current study is to characterize the change in stability and/or oligomeric status of the Toc complex with the incubation of nucleotides, analogs, proteins/peptides, etc. by blue native electrophoresis followed by 2d SDS-PAGE. The Toc complex ranges from ~800 kDa to greater than 1320 kDa for the proposed Toc/Tic supercomplex when no proteolytic degradation has occurred. Proteolytic degradation of Toc159 is correlated with the appearance of complexes with a mass ranging from 800 kDa to 440 kDa and below. Proteolytic degradation of Toc159 is more apparent in chloroplasts purified from older Pisum sativum plants. The results of the incubation of chloroplasts with GDP, GTP, and non-hydrolyzable analogs before analysis by 2d electrophoresis followed by western blot hybridization suggest that the loading of the GTPase receptors with nucleotide triphosphate results in the increased association of Toc components in complexes in the size range of 880- 630 kDa.

Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1991. / Maps in pocket. Vita. Abstract. Includes bibliographical references (leaves 186-189). Also available via the Internet.

Thesis (Ph. D.)--University of Alberta, 2009. / Title from PDF file main screen (viewed on Nov. 27, 2009). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Structural Engineering, Department of Civil and Environmental Engineering, University of Alberta." Includes bibliographical references.

Thesis (M.S.)--Central Connecticut State University, 2001. / Thesis advisor: Charles W. Dimmick. " ... in partial fulfillment of the requirements for the degree of Master of Science in Physics and Earth Sciences." Includes bibliographical references (leaves 60-64). Also available via the World Wide Web.

Thesis (Ph. D.)--University of Texas at Austin, 2003. / Vita. Includes bibliographical references. Available also from UMI Company.

Thesis (Ph. D.)--Institute of Technology, Otaniemi. / Bibliography: p. [89]-91.

Thesis (doctoral)--Université de Rennes I, 2003. / Includes bibliographical references. Also available on the Internet.

Thesis (doctoral)--Universiteit van Amsterdam, 1934. / Summary also in Dutch. Includes bibliographical references.

Thesis (doctoral)--Martin Luther-Universität Halle-Wittenberg, 1933. / Includes bibliographical references (p. 105-111).

Thèse--Faculté des lettres, Paris. / Includes bibliographical references.