LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 2 of total 2

Search options

  1. Article ; Online: Ultrafast CO Kinetics in Heme Proteins: Adiabatic Ligand Binding and Heavy Atom Tunneling.

    Benabbas, Abdelkrim / Sun, Yuhan / Poulos, Thomas L / Champion, Paul M

    Journal of the American Chemical Society

    2017  Volume 139, Issue 44, Page(s) 15738–15747

    Abstract: ... measured over a wide temperature range and compared with the kinetics of CO binding in other heme systems ... The ultrafast kinetics of CO rebinding to carbon monoxide oxidation activator protein (ChCooA) are ... such as myoglobin (Mb) and hemoglobin (Hb). The Arrhenius prefactor for CO binding to ChCooA and protoheme (∼10 ...

    Abstract The ultrafast kinetics of CO rebinding to carbon monoxide oxidation activator protein (ChCooA) are measured over a wide temperature range and compared with the kinetics of CO binding in other heme systems such as myoglobin (Mb) and hemoglobin (Hb). The Arrhenius prefactor for CO binding to ChCooA and protoheme (∼10
    MeSH term(s) Carbon Monoxide/metabolism ; Heme/metabolism ; Hemoglobins/chemistry ; Hemoglobins/metabolism ; Kinetics ; Ligands ; Myoglobin/chemistry ; Myoglobin/metabolism ; Protein Binding ; Quantum Theory ; Thermodynamics
    Chemical Substances Hemoglobins ; Ligands ; Myoglobin ; Heme (42VZT0U6YR) ; Carbon Monoxide (7U1EE4V452)
    Language English
    Publishing date 2017--08
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 3155-0
    ISSN 1520-5126 ; 0002-7863
    ISSN (online) 1520-5126
    ISSN 0002-7863
    DOI 10.1021/jacs.7b07507
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 4' 55/32: Show issues
    Z 7.3: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  2. Article: Ultrafast CO Kinetics in Heme Proteins: Adiabatic Ligand Binding and Heavy Atom Tunneling

    Benabbas, Abdelkrim / Paul M. Champion / Thomas L. Poulos / Yuhan Sun

    Journal of the American Chemical Society. 2017 Nov. 08, v. 139, no. 44

    2017  

    Abstract: ... measured over a wide temperature range and compared with the kinetics of CO binding in other heme systems ... 1) is similar to what is found for spin-allowed NO binding to heme proteins and is several orders ... The ultrafast kinetics of CO rebinding to carbon monoxide oxidation activator protein (ChCooA) are ...

    Abstract The ultrafast kinetics of CO rebinding to carbon monoxide oxidation activator protein (ChCooA) are measured over a wide temperature range and compared with the kinetics of CO binding in other heme systems such as myoglobin (Mb) and hemoglobin (Hb). The Arrhenius prefactor for CO binding to ChCooA and protoheme (∼1011 s–1) is similar to what is found for spin-allowed NO binding to heme proteins and is several orders of magnitude larger than the prefactor of Mb and Hb (∼109 s–1). This indicates that the CO binding reaction is adiabatic, in contrast to the commonly held view that it is nonadiabatic due to spin-forbidden (ΔS = 2) selection rules. Under the adiabatic condition, entropic factors, rather than spin-selection rules, are the source of the reduced Arrhenius prefactors associated with CO binding in Mb and Hb. The kinetic response of ChCooA-CO is nonexponential at all temperatures, including 298 K, and is described quantitatively using a distribution of enthalpic rebinding barriers associated with heterogeneity in the heme doming conformation. Above the solvent glass transition (Tg ∼ 180 K), the rebinding progress slows as temperature increases, and this is ascribed to an evolution of the distribution toward increased heme doming and larger enthalpic barriers. Between Tg and ∼60 K, the nonexponential rebinding slows down as the temperature is lowered and the survival fraction follows the predictions expected for a quenched barrier distribution. Below ∼60 K the rebinding kinetics do not follow these predictions unless quantum mechanical tunneling along the heme doming coordinate is also included as an active channel for CO binding.
    Keywords carbon monoxide ; glass transition ; heme ; heme proteins ; hemoglobin ; ligands ; myoglobin ; nitric oxide ; oxidation ; prediction ; quantum mechanics ; solvents ; temperature
    Language English
    Dates of publication 2017-1108
    Size p. 15738-15747.
    Publishing place American Chemical Society
    Document type Article
    ZDB-ID 3155-0
    ISSN 1520-5126 ; 0002-7863
    ISSN (online) 1520-5126
    ISSN 0002-7863
    DOI 10.1021/jacs.7b07507
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 4' 55/32: Show issues
    Z 7.3: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

To top