• Corpus ID: 24362978

Affinity labeling of the pyridoxal phosphate binding site of the beta2 subunit of Escherichia coli tryptophan synthase.

  title={Affinity labeling of the pyridoxal phosphate binding site of the beta2 subunit of Escherichia coli tryptophan synthase.},
  author={W. Higgins and E. W. Miles},
  journal={The Journal of biological chemistry},
  volume={253 13},
We have synthesized bromoacetylpyridoxamine phosphate and bromoacetylpyridoxamine and have shown that they meet three criteria for affinity labels of the beta2 subunit of tryptophan synthase: (i) the kinetic data of inactivation indicate that a binary complex is formed prior to covalent attachment; (ii) inactivation is largely prevented by the presence of pyridoxal phosphate; and (iii) inactivation is stoichiometric with incorporation of 0.7 to 0.8 mol of chromophore/mol of beta monomer. Our… 
Specific labeling of the active site of cytosolic aspartate aminotransferase through the use of a cofactor analogue, N-(Bromoacetyl)pyridoxamine.
Evidence is presented indicating that the pK of Lys-258 appears to be highly dependent upon the electrostatic state of neighboring groups in the active site region, and experimentally obtained values vary according to the chemical nature and charge of the modifying agent or probe.
Functional role of cysteinyl residues in tryptophanase.
The essential role of the active-site-bound pyridoxal 5'-phosphate in protection against inactivation was confirmed and the possible role of cysteinyl residues in the function of tryptophanase is discussed.
Circular-dichroism study of the interaction of aspartate-aminotransferase isoenzymes with a coenzyme analog.
The interaction between a coenzyme derivative, 4'-N-(2,4-dinitro-5-fluorophenyl)-pyridoxamine 5'-phosphate, and the apoenzyme of cytoplasmic and mitochondrial aspartate aminotransferase, was studied
Location of the reactive sulfhydryl residues in the primary sequence of the beta 2 subunit of tryptophan synthase of Escherichia coli.
It is shown that the single sulfhydryl which reacts with N-ethylmaleimide in the presence of pyridoxal phosphate is cysteine-170.
Affinity labeling of pig kidney 3,4-dihydroxyphenylalanine (Dopa) decarboxylase with N-(bromoacetyl)pyridoxamine 5'-phosphate. Modification of an active-site cysteine.
The overall conclusion is that Cys111 may be at, or near, the pyridoxal-5'-phosphate binding site of pig kidney Dopa decarboxylase and plays a critical role in the catalytic function of the enzyme.
Preparation of peptide-protein immunogens using N-succinimidyl bromoacetate as a heterobifunctional crosslinking reagent.
Synthetic peptides derived from human fibrin were unidirectionally conjugated to three carrier proteins by a method that employs N-succinimidyl bromoacetate, a heterobifunctional crosslinking reagent prepared with a 79% yield in gram quantities from inexpensive starting materials.
Comparison of blocked and non-blocked ricin-antibody immunotoxins against human gastric carcinoma and colorectal adenocarcinoma cell lines
The results showed that the blocked thioether IT displayed a more selective toxicity to target cells than the non-blocked IT and was much more potent than the ricin A chain conjugate.
L-Methionine γ-Lyase: Its Essential Cysteine Residues
L-Methionine γ-lyase is composed of four identical polypeptide chains, and contains 4 cysteinyl residues per subunit. One of them is catalytically essential, and the amino acid sequence around it was


hp://w w w .jb.org/ D ow nladed from 4652 New Affinity Labels for a Pyridoxal Phosphate Binding Site by gest on A uust 29
  • Rio&em. Biophys. Res. Commun
  • 1972