Manage your Funding Opportunities

Ninian Blackburn Institute of Environmental Health

Empty picture place holder

Ninian Blackburn


Manage your Funding

Scopus Publication Detail

The publication detail shows the title, authors (with indicators showing other profiled authors), information on the publishing organization, abstract and a link to the article in Scopus. This abstract is what is used to create the fingerprint of the publication.

A copper-methionine interaction controls the pH-dependent activation of peptidylglycine monooxygenase

Andrew T. Bauman; Brenda A. Broers; Chelsey D. Kline; Ninian J. Blackburn

(Profiled Author: Ninian Blackburn)

Biochemistry. 2011;50(50):10819-10828.


The pH dependence of native peptidylglycine monooxygenase (PHM) and its M314H variant has been studied in detail. For wild-type (WT) PHM, the intensity of the Cu-S interaction visible in the Cu(I) extended X-ray absorption fine structure (EXAFS) data is inversely proportional to catalytic activity over the pH range of 3-8. A previous model based on more limited data was interpreted in terms of two protein conformations involving an inactive Met-on form and an active flexible Met-off form [Bauman, A. T., et al. (2006) Biochemistry 45, 11140-11150] that derived its catalytic activity from the ability to couple into vibrational modes critical for proton tunneling. The new studies comparing the WT and M314H variant have led to the evolution of this model, in which the Met-on form has been found to be derived from coordination of an additional Met residue, rather than a more rigid conformer of M314 as previously proposed. The catalytic activity of the mutant decreased by 96% because of effects on both k cat and K M, but it displayed the same activity-pH profile with a maximum around pH 6. At pH 8, the reduced Cu(I) form gave spectra that could be simulated by replacement of the Cu M Cu-S(Met) interaction with a Cu-N/O interaction, but the data did not unambiguously assign the ligand to the imidazole side chain of H314. At pH 3.5, the EXAFS still showed the presence of a strong Cu-S interaction, establishing that the Met-on form observed at low pH in WT cannot be due to a strengthening of the Cu M-methionine interaction but must arise from a different Cu-S interaction. Therefore, lowering the pH causes a conformational change at one of the Cu centers that brings a new S donor residue into a favorable orientation for coordination to copper and generates an inactive form. Cys coordination is unlikely because all Cys residues in PHM are engaged in disulfide cross-links. Sequence comparison with the PHM homologues tyramine β-monooxygenase and dopamine β-monooxygenase suggests that M109 (adjacent to H site ligands H107 and H108) is the most likely candidate. A model is presented in which H108 is protonated with a pK a of 4.6 to generate the inactive low-pH form with Cu H coordinated by M109, H107, and H172. © 2011 American Chemical Society.

PMID: 22080626     PMCID: PMC3273323    

Scientific Context

This section shows information related to the publication - computed using the fingerprint of the publication - including related publications, related experts with fingerprints representing significant amounts of overlap between their fingerprint and this publication. The red dots indicate whether those experts or terms appear within the publication, thereby showing potential and actual connections.

Related Publications

Related Topics

Appears in this Publication Appears in this Document

Related Experts

Author of this Publication Author of this Document