Changes in absorption spectrum and crystal structure of triose phosphate isomerase brought about by 2-phosphoglycollate, a potential transition state analogue

1970 ◽  
Vol 47 (1) ◽  
pp. 93-100 ◽  
Author(s):  
L.N. Johnson ◽  
R. Wolfenden
Keyword(s):  
Crystal Structure ◽  
Absorption Spectrum ◽  
Transition State ◽  
Triose Phosphate Isomerase ◽  
Triose Phosphate ◽  
Transition State Analogue

Crystal structure of cobra-venom phospholipase A2 in a complex with a transition-state analogue

Science ◽  
1990 ◽  
Vol 250 (4987) ◽  
pp. 1560-1563 ◽  
Author(s):  
S. White ◽  
D. Scott ◽  
Z. Otwinowski ◽  
M. Gelb ◽  
P. Sigler
Keyword(s):  
Crystal Structure ◽  
Transition State ◽  
Phospholipase A2 ◽  
Cobra Venom ◽  
Transition State Analogue

scholarly journals Enzyme-substrate and enzyme-inhibitor complexes of triose phosphate isomerase studied by 31P nuclear magnetic resonance

1979 ◽  
Vol 179 (3) ◽  
pp. 607-621 ◽  
Author(s):  
I D Campbell ◽  
R B Jones ◽  
P A Kiener ◽  
S G Waley
Keyword(s):  
Enzyme Inhibitor ◽  
Ph Dependence ◽  
Triose Phosphate Isomerase ◽  
Dihydroxyacetone Phosphate ◽  
Ligand Complex ◽  
Triose Phosphate ◽  
Kinetic Information ◽  
Transition State Analogue ◽  
Chicken Muscle ◽  
Proton Uptake

The complex formed between the enzyme triose phosphate isomerase (EC 5.3.1.1.), from rabbit and chicken muscle, and its substrate dihydroxyacetone phosphate was studied by 31P n.m.r. Two other enzyme-ligant complexes examined were those formed by glycerol 3-phosphate (a substrate analogue) and by 2-phosphoglycollate (potential transition-state analogue). Separate resonances were observed in the 31P n.m.r. spectrum for free and bound 2-phosphoglycollate, and this sets an upper limit to the rate constant for dissociation of the enzyme-inhibitor complex; the linewidth of the resonance assigned to the bound inhibitor provided further kinetic information. The position of this resonance did not vary with pH but remained close to that of the fully ionized form of the free 2-phosphoglycollate. It is the fully ionized form of this ligand that binds to the enzyme. The proton uptake that accompanies binding shows protonation of a group on the enzyme. On the basis of chemical and crystallographic information [Hartman (1971) Biochemistry 10, 146–154; Miller & Waley (1971) Biochem. J. 123, 163–170; De la Mare, Coulson, Knowles, Priddle & Offord 1972) Biochem. J. 129, 321–331; Phillips, Rivers, Sternberg, Thornton & Wilson (1977) Biochem. Soc. Trans. 5, 642–647] this group is believed to be glutamate-165. On the other hand, the position of the resonance of D-glycerol 3 phosphate (sn-glycerol 1-phosphate) in the enzyme-ligand complex changes with pH, and both monoanion and dianon of the ligand bind, although dianion binds better. The substrate, dihydroxyacetone phosphate, behaves essentially like glycerol 3-phosphate. The experiments with dihydroxy-acetone phosphate and triose phosphate isomerase have to be carried out at 1 degree C because at 37 degrees C there is conversion into methyl glyoxal and orthophosphate. The mechanismof the enzymic reaction and the reasons for rate-enhancement are considered, and aspects of the pH-dependence are discussed in an Appendix.

Structure and Conformations of Gaba-Transaminase Inhibitors. II. Transition-State Analogs

1986 ◽  
Vol 39 (10) ◽  
pp. 1575 ◽  
Author(s):  
PR Andrews ◽  
V Cody ◽  
JM Gulbis ◽  
MN Iskander ◽  
AI Jeffrey ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Transition State ◽  
Crystal Structures ◽  
Gaba Transaminase ◽  
Preceding Article ◽  
Transition State Analogs ◽  
Calculated Energy ◽  
Transition State Analogue ◽  
Oxazine Ring ◽  
Transition State Analogue Inhibitors

Crystal structures of two benzoxazine derivatives designed as transition state analogue inhibitors of GABA-T were determined. These cyclic oxazine structures are shown to be more similar to the proposed transition state than the pyridoxal derivatives reported in the preceding article.1 Conformational analyses (non-bonded energy, MINDO/3, MNDO) show that the crystal structures are close to the calculated energy minima. The MNDO parameterization gives geometries close to the crystal structure, with the configuration at the nitrogen of the oxazine ring in particular being better reproduced than by the MINDO/3 method, which tends to prefer planar (sp2) nitrogen.

Crystal structure of bee-venom phospholipase A2 in a complex with a transition-state analogue

Science ◽  
1990 ◽  
Vol 250 (4987) ◽  
pp. 1563-1566 ◽  
Author(s):  
D. Scott ◽  
Z. Otwinowski ◽  
M. Gelb ◽  
P. Sigler
Keyword(s):  
Crystal Structure ◽  
Transition State ◽  
Phospholipase A2 ◽  
Bee Venom ◽  
Transition State Analogue
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