TY  - JOUR
A1  - Baxa, Ulrich
A1  - Steinbacher, Stefan
A1  - Weintraub, Andrej
A1  - Huber, Robert
A1  - Seckler, Robert
T1  - Mutations improving the folding of phage P22 tailspike protein affect its receptor binfing activity
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Baxa, Ulrich
A1  - Weintraub, Andrej
A1  - Seckler, Robert
T1  - Self-competitive inhibition of the bacteriophage P22 Tailspike endorhamnosidase by O-antigen oligosaccharides
JF  - Biochemistry
N2  - The P22 tailspike endorhamnosidase confers the high specificity of bacteriophage P22 for some serogroups of Salmonella differing only slightly in their O-antigen polysaccharide. We used several biophysical methods to study the binding and hydrolysis of O-antigen fragments of different lengths by P22 tailspike protein. O-Antigen saccharides of defined length labeled with fluorophors could be purified with higher resolution than previously possible. Small amounts of naturally occurring variations of 0antigen fragments missing the nonreducing terminal galactose could be used to determine the contribution of this part to the free energy of binding to be similar to 7 kJ/mol. We were able to show via several independent lines of evidence that an unproductive binding mode is highly favored in binding over all other possible binding modes leading to hydrolysis. This is true even under circumstances under which the O-antigen fragment is long enough to be cleaved efficiently by the enzyme. The high-affinity unproductive binding mode results in a strong self-competitive inhibition in addition to product inhibition observed for this system. Self-competitive inhibition is observed for all substrates that have a free reducing end rhamnose. Naturally occurring O-antigen, while still attached to the bacterial outer membrane, does not have a free reducing end and therefore does not perform self-competitive inhibition.
Y1  - 2020
U6  - https://doi.org/10.1021/acs.biochem.0c00872
SN  - 0006-2960
VL  - 59
IS  - 51
SP  - 4845
EP  - 4855
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Landström, Jens
A1  - Nordmark, Eva-Lisa
A1  - Eklund, Robert
A1  - Weintraub, Andrej
A1  - Seckler, Robert
A1  - Widmalm, Göran
T1  - Interaction of a Salmonella enteritidis O-antigen octasaccharide with the phage P22 tailspike protein by NMR spectroscopy and docking studies
N2  - The tailspike protein P22 recognizes an octasaccharide derived from the O-antigen polysaccharide of Salmonella enteritidis in a shallow groove and molecular docking successfully identifies this binding region on the protein surface. Analysis by 2D 1H,1H-T-ROESY and transferred NOESY NMR experiments indicate that the bound octasaccharide ligand has a conformation similar to that observed in solution. The results from a saturation transfer difference NMR experiment show that a large number of protons in the octasaccharide are in close contact with the protein as a result of binding. A comparison of the crystal structure of the complex and a molecular dynamics simulation of the octasaccharide with explicit water molecules suggest that only minor conformational changes are needed upon binding to the tailspike protein.
Y1  - 2008
UR  - http://www.springerlink.com/content/w3146138p25r2456/
U6  - https://doi.org/10.1007/s10719-007-9065-9
SN  - 0282-0080
ER  -