Methods for profiling the activity of enzymes in vivo are needed to understand the role that these proteins and their endogenous regulators play in physiological and pathological processes. This thesis describes the introduction and optimization of a tag-free strategy for activity-based protein profiling (ABPP) that utilizes the copper(I)-catalyzed azide-alkyne cycloaddition reaction ("click" chemistry) to analyze the functional state of enzymes in living cells and organisms. We show that enzymes can be labeled in an activity-based manner both in vitro and in vivo by an azido and alkynyl phenyl sulfonate ester probe and that these labeling events can be detected in whole proteomes by copper-catalyzed ligation with the complementary rhodamine-alkyne or -azide tag. We report a detailed characterization of the reaction parameters that affect click chemistry-based ABPP and identify conditions that maximize the speed, sensitivity, and bioorthogonality of this approach. Using these optimized conditions, we compare the enzyme activity profiles of living and homogenized breast cancer cells, resulting in the identification of several enzymes that are labeled by activity-based probes in situ but not in vitro. One of the most critical aspects of activity-based protein profiling methodology is determining whether or not labeling events are truly activity-based. Controls such as the comparative profiling of native and heat-denatured proteomes can provide great insight into the nature of the labeling event; however, to formally establish that probe labeling occurs in an activity-dependent manner, it is necessary to identify the site of modification. This is particularly important for in situ and in vivo labeling experiments, which are not amenable to the use of protein denaturation as biochemical controls. We report a tandem orthogonal on-bead proteolysis (TOP) strategy for the parallel identification of enzyme activities and sites of modification. Click chemistry is used to introduce a biotin tag with an orthogonal protease cleavage domain, which for the selective elution of active site peptides following on-bead trypsin digestion. Preliminary results using this TOP-ABPP to identify sites of alkyne-phenyl sulfonate labeling are presented.
... (blue/light-blue and red/brown) of the enzyme and also at an interface between the two domains of each subunit (blue and light-blue; red and brown). Imada, K. etal.: J. Mol. Biol. 1991, 222:725–738. References Imada, K. et al.
本书内容包括了大豆的化学组成、大豆蛋白质的营养价值、大豆蛋白制品生产、大豆在乳品工业中的应用、大豆蛋白质在面糖制品及其他食品中的应用等。
The current list of Specialist Periodical Reports can be seen on the inside flap of this volume.
The current list of Specialist Periodical Reports can be seen on the inside flap of this volume.
This book addresses one of the fundamental problems of cell biology, namely how proteins are sent to and maintained at their correct destinations within cells.
Protein Targeting: 8th John Innes Symposium : Papers
This volume provides a collection of contemporary perspectives on using activity-based protein profiling (ABPP) for biological discoveries in protein science, microbiology, and immunology.
A protein may undergo reversible structural changes in performing its biological function. This book presents current research in the study of protein structure.
There are several ways to represent the structure of a protein, and sophisticated computer technology has been applied to provide them in visually exciting ways. Technical details of all of...
This second edition volume expands on the previous edition with an update on the latest developments in the field and new techniques used to study secondary and supersecondary structures (SSS) in proteins.