scholarly journals A monoclonal antibody to aromatic amino acid hydroxylases. Identification of the epitope

1988 ◽  
Vol 255 (1) ◽  
pp. 193-196 ◽  
Author(s):  
R G H Cotton ◽  
W McAdam ◽  
I Jennings ◽  
F J Morgan
Keyword(s):  
Monoclonal Antibody ◽  
Amino Acid ◽  
Aromatic Amino Acid ◽  
Tryptophan Hydroxylase ◽  
Phenylalanine Hydroxylase ◽  
Amino Acid Residues ◽  
Vertebrate Species ◽  
Wide Range ◽  
Human Phenylalanine Hydroxylase ◽  
Aromatic Amino Acid Hydroxylases

PH8 monoclonal antibody has previously been shown to react with all three aromatic amino acid hydroxylases, being particularly useful for immunohistochemical staining of brain tissue [Haan, Jennings, Cuello, Nakata, Chow, Kushinsky, Brittingham & Cotton (1987) Brain Res. 426, 19-27]. Western-blot analysis of liver extracts showed that PH8 reacted with phenylalanine hydroxylase from a wide range of vertebrate species. The epitope for antibody PH8 has been localized to the human phenylalanine hydroxylase sequence between amino acid residues 139 and 155. This highly conserved region of the aromatic amino acid hydroxylases has 11 out of 17 amino acids identical in phenylalanine hydroxylase, tyrosine hydroxylase and tryptophan hydroxylase.

Assignment of human tryptophan hydroxylase locus to chromosome 11: Gene duplication and translocation in evolution of aromatic amino acid hydroxylases

1987 ◽  
Vol 13 (5) ◽  
pp. 575-580 ◽  
Author(s):  
Fred D. Ledley ◽  
Hernan E. Grenett ◽  
David P. Bartos ◽  
Peter Tuinen ◽  
David H. Ledbetter ◽  
...  
Keyword(s):  
Amino Acid ◽  
Gene Duplication ◽  
Aromatic Amino Acid ◽  
Tryptophan Hydroxylase ◽  
Chromosome 11 ◽  
Aromatic Amino Acid Hydroxylases

Three classes of tetrahydrobiopterin-dependent enzymes

Pteridines ◽  
2013 ◽  
Vol 24 (1) ◽  
pp. 7-11
Author(s):  
Ernst R. Werner
Keyword(s):  
Nitric Oxide ◽  
Amino Acid ◽  
Protein Sequence ◽  
Aromatic Amino Acid ◽  
Phenylalanine Hydroxylase ◽  
Current Knowledge ◽  
Sequence Similarity ◽  
Protein Sequences ◽  
Nitric Oxide Synthases ◽  
Aromatic Amino Acid Hydroxylases

AbstractCurrent knowledge distinguishes three classes of tetrahydrobiopterin-dependent enzymes as based on protein sequence similarity. These three protein sequence clusters hydroxylate three types of substrate atoms and use three different forms of iron for catalysis. The first class to be discovered was the aromatic amino acid hydroxylases, which, in mammals, include phenylalanine hydroxylase, tyrosine hydroxylase, and two isoforms of tryptophan hydroxylases. The protein sequences of these tetrahydrobiopterin-dependent aromatic amino acid hydroxylases are significantly similar, and all mammalian aromatic amino acid hydroxylases require a non-heme-bound iron atom in the active site of the enzyme for catalysis. The second classes of tetrahydrobiopterin-dependent enzymes to be characterized were the nitric oxide synthases, which in mammals occur as three isoforms. Nitric oxide synthase protein sequences form a separate cluster of homologous sequences with no similarity to aromatic amino acid hydroxylase protein sequences. In contrast to aromatic amino acid hydroxylases, nitric oxide synthases require a heme-bound iron for catalysis. The alkylglycerol monooxygenase protein sequence was the most recent to be characterized. This sequence shares no similarity with aromatic amino acid hydroxylases and nitric oxide synthases. Motifs contained in the alkylglycerol monooxygenase protein sequence suggest that this enzyme may use a di-iron center for catalysis.

scholarly journals Glyceryl ether monooxygenase resembles aromatic amino acid hydroxylases in metal ion and tetrahydrobiopterin dependence

2009 ◽  
Vol 390 (1) ◽  
Author(s):  
Katrin Watschinger ◽  
Markus A. Keller ◽  
Albin Hermetter ◽  
Georg Golderer ◽  
Gabriele Werner-Felmayer ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Amino Acid ◽  
Aromatic Amino Acid ◽  
Glyceryl Ether ◽  
Metal Ion ◽  
Phenylalanine Hydroxylase ◽  
Heme Iron ◽  
Non Heme Iron ◽  
Oxide Synthase ◽  
Aromatic Amino Acid Hydroxylases

Abstract Glyceryl ether monooxygenase is a tetrahydrobiopterin-dependent membrane-bound enzyme which catalyses the cleavage of lipid ethers into glycerol and the corresponding aldehyde. Despite many different characterisation and purification attempts, so far no gene and primary sequence have been assigned to this enzyme. The seven other tetrahydrobiopterin-dependent enzymes can be divided in the family of aromatic amino acid hydroxylases – comprising phenylalanine hydroxylase, tyrosine hydroxylase and the two tryptophan hydroxylases – and into the three nitric oxide synthases. We tested the influences of different metal ions and metal ion chelators on glyceryl ether monooxygenase, phenylalanine hydroxylase and nitric oxide synthase activity to elucidate the relationship of glyceryl ether monooxygenase to these two families. 1,10-Phenanthroline, an inhibitor of non-heme iron-dependent enzymes, was able to potently block glyceryl ether monooxygenase as well as phenylalanine hydroxylase, but had no effect on inducible nitric oxide synthase. Two tetrahydrobiopterin analogues, N5-methyltetrahydrobiopterin and 4-aminotetrahydrobiopterin, had a similar impact on glyceryl ether monooxygenase activity, as has already been shown for phenylalanine hydroxylase. These observations point to a close analogy of the role of tetrahydrobiopterin in glyceryl ether monooxygenase and in aromatic amino acid hydroxylases and suggest that glyceryl ether monooxygenase may require a non-heme iron for catalysis.

A Factor VIII Neutralizing Monoclonal Antibody and a Human Inhibitor Alloantibody Recognizing Epitopes in the C2 Domain Inhibit Factor VIII Binding to von Willebrand Factor and to Phosphatidylserine

1993 ◽  
Vol 69 (03) ◽  
pp. 240-246 ◽  
Author(s):  
Midori Shima ◽  
Dorothea Scandella ◽  
Akira Yoshioka ◽  
Hiroaki Nakai ◽  
Ichiro Tanaka ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Amino Acid ◽  
Factor Viii ◽  
Von Willebrand Factor ◽  
Light Chain ◽  
Amino Acid Residues ◽  
Amino Terminal ◽  
Neutralizing Monoclonal Antibody ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryA neutralizing monoclonal antibody, NMC-VIII/5, recognizing the 72 kDa thrombin-proteolytic fragment of factor VIII light chain was obtained. Binding of the antibody to immobilized factor VIII (FVIII) was completely blocked by a light chain-specific human alloantibody, TK, which inhibits FVIII activity. Immunoblotting analysis with a panel of recombinant protein fragments of the C2 domain deleted from the amino-terminal or the carboxy-terminal ends demonstrated binding of NMC-VIII/5 to an epitope located between amino acid residues 2170 and 2327. On the other hand, the epitope of the inhibitor alloantibody, TK, was localized to 64 amino acid residues from 2248 to 2312 using the same recombinant fragments. NMC-VIII/5 and TK inhibited FVIII binding to immobilized von Willebrand factor (vWF). The IC50 of NMC-VIII/5 for the inhibition of binding to vWF was 0.23 μg/ml for IgG and 0.2 μg/ml for F(ab)'2. This concentration was 100-fold lower than that of a monoclonal antibody NMC-VIII/10 which recognizes the amino acid residues 1675 to 1684 within the amino-terminal portion of the light chain. The IC50 of TK was 11 μg/ml by IgG and 6.3 μg/ml by F(ab)'2. Furthermore, NMC-VIII/5 and TK also inhibited FVIII binding to immobilized phosphatidylserine. The IC50 for inhibition of phospholipid binding of NMC-VIII/5 and TK (anti-FVIII inhibitor titer of 300 Bethesda units/mg of IgG) was 10 μg/ml.

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