Chemical Biology Student Seminars – 2005

Spring

February 9

Tyler Heibeck
* Open to the public

“Development of a protein 3-nitrotyrosine identification method using solid phase capture”

Abstract

February 23

John Miecznikowski

“Iridium N-Heterocyclic Carbene Complexes in Transfer Hydrogenation Catalysis”

Abstract

March 2

Patrick Cappillino

March 9

Suzanne Hertzler

March 16

Abby Oelker

March 23

Gulbenk Anarat

May 4

Lauren Wolf

Fall

October 3

Truc Diep (Monday 2 – 3 pm Tullius Group)

“The Effect of a Single-nucleoside Gap in DNA on Cyclization Kinetics”

October 19

Long Xu (Tullius Group)

“Progress report on isolation and characterization of the yeast proteins recognizing oxidatively damaged DNA”

October 26

Lucian Postelmicu (Georgiadis Group)

“Hybridization of Platinum Drug Adducts”

November 2

Yang Gao (Georgiadis Group)

“Secondary Structure Effects on DNA Hybridization in Solution and on Surfaces”

November 9

Jiandi Wan (Jones Group)

“Detection Device Development: from microfluidic chips to surface chemistry”

November 16

Guangcheng Dong (Tullius Group)

November 23

Tao Ye (Elliott Group)

“Electrochemical investigation of CueO: a periplasmic mutlicopper oxidase from E. coli”

November 30

SuzAnn Hertzler (Caradonna Group)

“Comparative Studies of SelectMutants of Phenylalanine and Tyrosine Hydroxylases: Understandingthe Chemical Basis of Clinical Pathology”

December 13

Abby Oelker (Tueday 3 – 4 pm Grinstaff Group)

“Hydrogels for Artificial Cornea Constructs”

Tyler Heibeck
3-Nitrotyrosine is produced by the reaction of various redox reactive
nitrogen species, notably peroxynitrite, which is produced under
normal physiological conditions and in increased amounts under
conditions of oxidant stress. To that end, 3-nitrotyrosine is a
potential marker for oxidative stress induced modifications in
proteins. Current detection methods do not allow for location of the
point of modification or are too insensitive. Using chemical
modification, solid phase capture, and mass spectrometric analysis
3-nitrotyrosine can be concentrated and identified within in vitro
nitrated protein. Current work is focused on increasing sensitivity
and applicability to complex protein mixtures.

John Miecznikowski
I will describe the synthesis and transfer-hydrogenation activity of
chelating bis-N-heterocyclic carbene complexes of iridium and rhodium. The
chelating bis-N-heterocyclic carbene ligands are robust ligands and, once
bound to the metal, exhibit remarkable thermal, air, and moisture
stability, which are very useful features for homogenous catalysis. These
precatalysts were screened for transfer hydrogenation activity of ketones,
aldehydes, enolizable aldehydes, alpha,beta-unsaturated compounds, and
imines with either potassium hydroxide or alkali carbonates as
base. Chelating bis-imidazole and bis-triazole complexes are prepared and
their activities compared. Variation of the wingtip R-groups is also
explored. A mechanism for transfer hydrogenation of these precatalysts is
proposed; catalyst reuse and selectivity is explored.