Streptococcal protein

Fig, 4. (a) Eigenvalues and distributions for the ct-carbon atoms in the 56-residue B l-domain of streptococcal protein G, from a 1 ns MD simulation in water (courtesy of Bort de Groot, Groningen). 

L. Bjoerck and G. Kronvall, Purification and some properties of streptococcal protein G, a novel IgG-binding reagent. J. Immunol. 133, 969-974 (1984). 

Very small proteins, such as 02, can have a very expanded Dphys (see Chapter 19, section B4). The IgG binding domain of streptococcal protein L (62 residues) is of similar size to 02 and also folds by two-state kinetics (see Tables... 

Bjorck, L., Kastem, W., Lindahl, G., and Wideback, K. (1987) Streptococcal protein G, expressed by streptococci or by Escherichia coli, has separate binding sites for human albumin and IgG. Mol. Immunol. 24,1113-1122. 

Moreira IS, Fernandes PA, Ramos MJ (2006) Unravelling die importance of protein-protein interaction application of a computational alanine scanning mutagenesis to the study of the IgGl streptococcal protein G (c2 Fragment) complex, J Phys Chem B, 110 10962... 

The final example is the results of the applications of REMD simulations to the folding of a small protein, namely, the Bl domain of streptococcal protein G [164]. The simulations were performed on the Earth Simulator. Protein G consists of 56 amino acids, and the total number of atoms in the protein is 855. For the force fields, we used OPLS-AA/L [165] for the protein molecule and TIP3P [143] for water molecules. We first performed a REMD simulation of protein G in vacuum with 96 replicas. The initial conformation of the REMD simulation was a fully extended one. We then solvated one of the obtained... 

Clore et a/.81 calculated a structure of the B1 domain of the streptococcal protein G (56 residues) by RDCs (for 15N-Hn, l 5N l3C. and HN 13 C ) and 32 backbone hydrogen bond constraints (Section 8.3) without NOE-derived distances. They compared structural convergences for their calculations using 152 RDCs measured in tobacco mosaic virus, 150 RDCs measured in DMPC/DHPC (3 1) bicelles, and without RDCs. The rmsd values with RDCs were both improved significantly (four-fold). A further improvement was observed for calculations using the two sets of the constraints simultaneously by 20-30%. This indicated that the alignment mechanisms are different and complementary to the two medias. 

Libon, C., Corvai a, N., Haeuw, J.F., Nguyen, T., Bormefoy, J.Y. and Andreoni, C., 1999, The serum albumin-binding region of Streptococcal protein G (BB) potentiates the immunogenicity of the G130-230 RS V-A protein. Vaccine 17 406-414. 

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