Tag Archives: protein modification

Les Miserables and the histone code

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Dr. Greg Buhrman

Dr. Greg Buhrman - First Time Teacher

By Greg Buhrman

OK, I admit I was getting a little desperate today. I’d started this class with the idea of teaching Cell Biology and along the way, explaining how normal cellular biology relates to the disease state, with a focus on cancer and diabetes. When I started organizing the class it made sense at the time. After all, I’ve spent the last ten years doing cancer research, mostly with Dr. Carla Mattos (my thesis mentor) and Dr. Jason Haugh (a committee member and collaborator in the Chemical Engineering Department) at NCSU and for a year or two (one year in his lab, two years if you count collaboration time) with Dr. Johannes Rudolph at Duke Univ. With that experience, I felt like I had a reasonable handle on enough aspects of cancer research to teach it. Diabetes is a disease that I’m just starting to work on now in Dr. Bob Rose’s lab at NCSU, so I felt like if I’m going to be learning about it anyway, I might as well incorporate it in the class.

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A genetically encoded site-specific label for protein imaging

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Rapid bioorthogonal labeling of proteins

Clay Clark

Clay Clark

By Clay Clark, @biochemprof

ResearchBlogging.org
There are a number of current methods for labeling proteins for imaging either in vitro and/or in live cells and organisms, including fusions with fluorescent proteins, dyes, tags (such as SNAP, HALO, CLIP), ligases, spin-labels, or unnatural amino acids. Some of the methods are summarized in the figure from Chen & Ting, which shows several approaches to labeling proteins with small molecules, either through fusion proteins (A), chemical or enzymatic labeling of a protein tag (B,C) or site-specific labeling using genetically encoded amber mutations (D).

protein labeling strategies

Protein labeling strategies, from Chen & Ting, DOI 10.1016/j.copbio.2004.12.003

In recent years, several chemical probes have been developed that allow the incorporation of reactive tags into proteins. The tags can then be modified within the complex mixture of the cellular milieu, providing a powerful technique to examine protein structure and function as well as interaction networks in native conditions (see review of the tags by Best).

While some of the tags allow rapid labeling and have been used in numerous cell biological studies, many of the methods result in the addition of extra amino acids to the protein, which may affect the protein structure or function. In addition, some of the chemical probes have slow reaction times, which limits their use.

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