Work

Measurement of Kinetics and Active Site Distances in Metalloenzymes Using Paramagnetic NMR with 13C Hyperpolarization

Year: 2018

Type: article

Abstract: Paramagnetic relaxation enhancement (PRE) conjoint with hyperpolarized NMR reveals structural information on the enzyme–product complex in an ongoing metalloenzyme-catalyzed reaction. Substrates of pseudouridine monophosphate glycosidase are hyperpolarized using the dynamic nuclear polarization (DNP) method. Time series of 13 C NMR spectra are subsequently measured with the enzyme containing diamagnetic Mg 2+ or paramagnetic Mn 2+ ions in the active site. The differences of the signal evolution and line widths in the Mg 2+ vs Mn 2+ reactions are explained through PRE in the enzyme-bound product, which is in fast exchange with its free form. Here, a strong distance dependence of the paramagnetically enhanced relaxation rates enables the calculation of distances from product atoms to the metal center in the complexed structure. The same method can be used to add structural information to real-time characterizations of chemical processes involving compounds with naturally present or artificially introduced paramagnetic sites.

Source: The Journal of Physical Chemistry Letters

DOI: 10.1021/acs.jpclett.8b00350

Authors: Mengxiao Liu, Guannan Zhang, Nilkamal Mahanta, Youngbok Lee, Christian Hilty

Institutions: Texas A&M University, Hanyang University

Language: English

Topic: Advanced NMR Techniques and Applications

Subfield: Spectroscopy

Field: Chemistry

Domain: Physical Sciences

Open Access status: green

Funders: Welch Foundation, National Institutes of Health, National Institute of General Medical Sciences, Division of Chemistry

Awards: G1020944575, G1737273289, Development of Platform for Ligand Screening using Hyperpolarized NMR, G5057096824