Proteins, introduction

Hediger, M.A., Romero, M.F., Peng, J.B., Rolfs, A., Takanaga, H. and Bruford, E.A. The ABCs of solute carriers Physiological, pathological and therapeutic implications of human membrane transport proteins. Introduction. Pfliigers Arch 447 465-468, 2004. 

Pollard, T. D. (1999). Actin and associated proteins Introduction. In Guidebook to the Cytoskeletal and Motor Proteins (T. Kreis and R. D. Vale, Eds.), pp. 3-110. Oxford University Press, Oxford. 

Because of the strict stereochemical requirements, it is not easy to find optimal sites for the introduction of disulfide bonds into proteins. Introduction of disulfide bonds into T4 lysozyme has been engineered by theoretical calculations and computer modeling.4 7 The results obtained from the mutant lysozymes illustrate several points relevant to the use of disulfide bonds for improving protein stability.6 (i) Introduction of the cysteine(s) should minimize the disruption or loss of interactions that stabilize the native structure, (ii) The size of the loop formed by the crosslink should be as large as possible, (iii) The strain energy introduced by the disulfide bond should be kept as low as possible. For this purpose, a location within the flexible part of the molecule is desirable. 

The ABCs of solute carriers physiological, pathological and therapeutic implications ofhuman membrane transport proteins introduction. Pflugers Archives, 447, 465-468. 

Polypeptides. These are strings of a-amino acids usually with the natural 5(L) [L-cysteine is an exception and has the R absolute configuration] or sometimes unnatural R(D) configuration at die a-carbon atom. They generally have less than 100 amino acid residues. They can be naturally occurring or, because of their small size, can be synthesised chemically from the desired amino acids. Their properties can be very similar to those of small proteins. Many are commercially available, and can be custom made commercially or locally with a peptide synthesiser. They are purified by HPLC and can be used without further purification. Their purity can be checked as described under proteins (Introduction). 

Cellulose acetate, polyacrylamide gel electrophoresis, serum proteins. Introduction... 

Dunn MJ (1993) Gel Electrophoresis Proteins (Introduction to Biotechniques). Oxford BIOS Scientific Publishers Limited. 

A HiSg tag may be added at the N-terminus or C terminus of the protein to facilitate protein purification. A TEV protease recognition cleavage site (ENLYFQG) may be introduced to remove N-terminal fusion part ofthe target protein. Introduction of the TEV site to the C-terminal part of the target protein is not recommended. In the later case six unrelated amino acids are left at the C-terminal part of the protein. 

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