PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 8137931

How does NO activate hemeproteins?

A Tsai
View original source ↗Export metadata ↓

Abstract

NO was reported to activate guanylate cyclase and, recently, prostaglandin H synthase. NO interaction with the heme component in different hemeproteins is determined by ligand property, electronic configuration of the heme iron and the specific effects contributed by the protein structure. It is found that although NO interaction with the free heme provides some common rules of interaction, the consequences of NO binding to different hemeproteins should be dealt with individually.

Explore related subjects

HemeproteinsNitric OxideJournal ArticleReview

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

A Tsai. 1994-03-21. How does NO activate hemeproteins?. https://doi.org/10.1016/0014-5793(94)80445-1

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2006

Electronic ménages a trois: a molecular orbital perspective of protonated ferryl intermediates and synthetic models.

Presented here is a molecular orbital perspective of various S=1 iron(IV)-hydroxo compound II intermediates as well as of synthetic heme and nonheme analogues. A key conceptual issue concerns how the iron(IV) center in these species coexists with highly reducing alkoxide, thiolate, phenolate, and hydroperoxide ligands. We suggest that a clue to this conundrum involves a three-way splitting of the spin density among the iron and two pi-basic ligands, which effectively delocalizes the high positive charge away from the iron.

Hemeproteins↗
PubMed2005

Direct probe of iron vibrations elucidates NO activation of heme proteins.

We use nuclear resonance vibrational spectroscopy (NRVS) to identify the Fe-NO stretching frequency in the NO adduct of myoglobin (MbNO) and in the related six-coordinate porphyrin Fe(TPP)(1-MeIm)(NO). Frequency shifts observed in MbNO Raman spectra upon isotopic substitution of Fe or the nitrosyl nitrogen confirm and extend the NRVS results. In contrast with previous assignments, the Fe-NO frequency of these six-coordinate complexes lies 70-100 cm-1 lower than in the analogous five-coordinate nitrosyl complexes, indicating a significant weakening of the Fe-NO bond in the presence of a trans imidazole ligand. This result supports proposed mechanisms for NO activation of heme proteins and underscores the value of NRVS as a direct probe of metal reactivity in complex biomolecules.

Hemeproteins↗
PubMed2005

MauG-dependent in vitro biosynthesis of tryptophan tryptophylquinone in methylamine dehydrogenase.

Tryptophan tryptophylquinone (TTQ) is the prosthetic group of methylamine dehydrogenase (MADH) and is synthesized through post-translational modification of two endogenous tryptophan residues. This modification involves two oxygenation reactions and one cross-linking reaction. It is clearly shown that the incorporation of the second oxygen into betaTrp57 and the covalent cross-linking of betaTrp57 to betaTrp108 are MauG-dependent processes. These reaction steps are severely compromised in vivo when mauG is mutated or deleted. These steps may then be catalyzed in vitro upon addition of MauG to the isolated biosynthetic intermediates. These results also show that TTQ formation is linked to proper assembly of subunits during MADH biosynthesis. Last, these results demonstrate a novel function for the c-type heme protein, MauG, which is consistent with its atypical physical properties. These results are the first description of an enzyme-mediated biosynthesis of a protein-derived cofactor in vitro.

Hemeproteins↗