Orientation of Non-Native 2-Monosubstituted and 2,3-Disubstituted 1,4-Naphthoquinones in the A1 binding site of PSI and the effect on the rate of electron transfer : an electron paramagnetic resonance spectroscopy study

The proce-ss ofoxygenic photosynthesis is vital to life on Earth. the central event in photosynthesis is light induced electron transfer that converts light into energy for growth. Ofparticular significance is the membrane bound multisubunit protein known as Photosystem I (PSI). PSI is a reaction centre that is responsible for the transfer of electrons across the membrane to reduce NADP+ to NADPH. The recent publication ofa high resolution X-ray structure of PSI has shown new information about the structure, in particular the electron transfer cofactors, which allows us to study it in more detail. In PSI, the secondary acceptor is crucial for forward electron transfer. In this thesis, the effect of removing the native acceptor phylloquinone and replacing it with a series of structurally related quinones was investigated via transient electron paramagnetic resonance (EPR) experiments. The orientation of non native quinones in the binding site and their ability to function in the electron transfer process was determined. It was found that PSI will readily accept alkyl naphthoquinones and anthraquinone. Q band EPR experiments revealed that the non-native quinones are incorporated into the binding site with the same orientation of the headgroup as in the native system. X band EPR spectra and deuteration experiments indicate that monosubstituted naphthoquinones are bound to the Al site with their side group in the position occupied by the methyl group in native PSI (meta to the hydrogen bonded carbonyl oxygen). X band EPR experiments show that 2, 3- disubstituted methyl naphthoquinones are also incorporated into the Al site in the same orientation as phylloquinone, even with the presence of a halogen- or sulfur-containing side chain in the position normally occupied by the phytyl tail ofphylloquinone. The exception to this is 2-bromo-3-methyl --.- _. -. - -- - - 4 _._ _ _ - _ _ naphthoquinone which has a poorly resolved spectrum, making determination of the orientation difficuh. All of the non-native quinones studied act as efficient electron acceptors. However, forward electron transfer past the quinone could only be demonstrated for anthraquinone, which has a more negative midpoint potential than phylloquinone. In the case of anthraquinone, an increased rate of forward electron transfer compared to native PSI was found. From these results we can conclude that the rate ofelectron transfer from Al to Fx in native PSI lies in the normal region ofthe Marcus Curve.

Orange Union High School, Orange, California

Orange Union High School in Orange, California, ca. 1915. Elongated postcard image shows bird's-eye view looking southeast toward the campus. The original academic building in the center was designed by local architect C.B. Bradshaw and completed in July 1905 [now Wilkinson Hall]. The "Twins," identical buildings officially known as the Science and Commercial Buildings[now Reeves Hall and Smith Hall], flank the academic building on the north and south, forming a "U." They were added in 1913 and designed by Santa Ana architect Fred Eley. The 300 block of North Glassell Street runs in front of the buildings and East Palm Avenue is on the south side. Residences can be seen in front and behind the campus. The campus was purchased by Chapman College in 1954.

Orange Union High School, Orange, California

Orange Union High School in Orange, California, ca. 1915. Elongated postcard image shows bird's-eye view looking southeast toward the campus. The original academic building in the center was designed by local architect C.B. Bradshaw and completed in July 1905 [now Wilkinson Hall]. The "Twins," identical buildings officially known as the Science and Commercial Buildings[now Reeves Hall and Smith Hall], flank the academic building on the north and south, forming a "U." They were added in 1913 and designed by Santa Ana architect Fred Eley. The 300 block of North Glassell Street runs in front of the buildings and East Palm Avenue is on the south side. Residences can be seen in front and behind the campus. The campus was purchased in 1954 by Chapman College.

Speeches delivered by several Indians chiefs.. also an extract of a letter from an Indian chief

Reprint of the 1810 ed. printed by Samuel Wood, New York, Reprinted by Ipswich By J. Bush, Tavern-Street

Letter to S.D. Woodruff from Fred Holmes

Letter to S.D. Woodruff from Fred Holmes regarding the work done on the east side of the rail track. He gives the measurement of work done by W. Robinson, May 18, 1860.

Letter to S.D. Woodruff from Fred Holmes

Letter to S.D. Woodruff from Fred Holmes noting how many days work were done by him, William Stoker and Thomas Secord, Aug. 27, 1860.

Pay roll voucher #12 from the Engineer Department of Port Dalhousie and Thorold Railway Extension for the office approved by F. Shanly, chief engineer, April, 1857

Pay roll voucher #12 from the Engineer Department of Port Dalhousie and Thorold Railway Extension for the office approved by F. Shanly, chief engineer, April, 1857.

Pay roll voucher #13 from the Engineer Department of Port Dalhousie and Thorold Railway Extension for the Northern Division for the month of April, 1857 approved by F. Shanly, chief engineer and W.G. Thompson, assistant engineer, April 27, 1857

Pay roll voucher #13 from the Engineer Department of Port Dalhousie and Thorold Railway Extension for the Northern Division for the month of April, 1857 approved by F. Shanly, chief engineer and W.G. Thompson, assistant engineer, April 27, 1857.

Pay roll voucher #14 from the Engineer Department of Port Dalhousie and Thorold Railway Extension for the Southern Division for the month of April, 1857 approved by F. Shanly, chief engineer and Francis A. Doyle, assistant engineer, April 28, 1857

Pay roll voucher #14 from the Engineer Department of Port Dalhousie and Thorold Railway Extension for the Southern Division for the month of April, 1857 approved by F. Shanly, chief engineer and Francis A. Doyle, assistant engineer, April 28, 1857.

Pay roll voucher # 17 from the Engineer Department of Port Dalhousie and Thorold Railway Extension, for the Northern Division for the month of May, 1857, approved by F. Shanly, chief engineer and W.G. Thompson, assistant engineer, May 27, 1857

Pay roll voucher # 17 from the Engineer Department of Port Dalhousie and Thorold Railway Extension, for the Northern Division for the month of May, 1857, approved by F. Shanly, chief engineer and W.G. Thompson, assistant engineer, May 27, 1857.

Pay roll voucher #16 from the Engineer Department of Port Dalhousie and Thorold Railway Extension, for the office approved by F. Shanly, chief engineer, May 30, 1857

Pay roll voucher #16 from the Engineer Department of Port Dalhousie and Thorold Railway Extension, for the office approved by F. Shanly, chief engineer, May 30, 1857.

Pay roll voucher #18 from the Engineer Department of Port Dalhousie and Thorold Railway Extension, for the Southern Division approved by F. Shanly, chief engineer and F.A. Doyle assistant engineer, May 31, 1857

Pay roll voucher #18 from the Engineer Department of Port Dalhousie and Thorold Railway Extension, for the Southern Division approved by F. Shanly, chief engineer and F.A. Doyle assistant engineer, May 31, 1857.

Pay roll voucher #20 from the Engineer Department of Port Dalhousie and Thorold Railway Extension, for the Northern Division approved by F. Shanly, chief engineer and W.G. Thompson, assistant engineer (copy) June 1857

Pay roll voucher #20 from the Engineer Department of Port Dalhousie and Thorold Railway Extension, for the Northern Division approved by F. Shanly, chief engineer and W.G. Thompson, assistant engineer (copy) June 1857.

Pay roll voucher #21 from the Engineer Department of Port Dalhousie and Thorold Railway Extension, for the Southern Division approved by F. Shanly, chief engineer and Francis A. Doyle, assistant engineer (copy) June 29, 1857

Pay roll voucher #21 from the Engineer Department of Port Dalhousie and Thorold Railway Extension, for the Southern Division approved by F. Shanly, chief engineer and Francis A. Doyle, assistant engineer (copy) June 29, 1857.

Pay roll voucher #19 from the Port Dalhousie and Thorold Railway Extension, for the office approved by F. Shanly, chief engineer (copy), July 1, 1857

Pay roll voucher #19 from the Port Dalhousie and Thorold Railway Extension, for the office approved by F. Shanly, chief engineer (copy), July 1, 1857.