Avance II+ - 800 MHz

The AvanceII+ 800 spectrometer is particularly suitable for structural studies of small to medium size molecules, and especially for the determination of three dimensional structures of proteins in solution. On daily basis operation the spectrometer is equipped with a CP2.1 TCI-z H&F/C/N 5 mm inverse detection probe-head with actively cooled preamplifier electronics and a cold SampleCase allowing the storage, at 6ºC, up to 24 biological samples for automatic data acquisition. As secondary accessories three 5 mm inverse detection room-temperature (RT) probe-heads are also available (QXI-z C/N/P, TXI-z C/N and BBI-z, with broadband decoupling of X nuclei in the range from ³¹P to ¹⁰⁹Ag). This set of probe-heads allows the acquisition of conventional multidimensional correlation spectra, such as COSY, NOESY, TOCSY, HSQC, HMQC, HMBC or combinations such as HSQC-TOCSY or HSQC-NOESY, and common triple resonance spectra like HNCA, HNCOCA, HNCB, HNCACB, etc., with or without the TROSY detection scheme for higher resolution in medium sized proteins. Apart from the experiments directed to structure determination, it is also possible to perform dynamic studies using relaxation data, fast proton/deuterium exchange (CLEANEX sequence), diffusion spectroscopy (DOSY), metabolomics analysis and J-resolved spectroscopy.

This spectrometer is also equipped with a 10 mm QNP C/N/P probe-head mainly intended for metabolomics and in vivo NMR studies in microorganisms, cells, tissues or small organs (those that will fit into 10 mm tubes) as well as a 5 mm BBO-z, with broadband decoupling of X nuclei (in the range from ³¹P to ¹⁰⁹Ag) allowing the direct observation of less common nuclei such asSilicon, Selenium, Cadmium, Cobalt, Sodium, and Potassium, among others.

Description and history of the equipment:

The spectrometer was acquired by the Rede Nacional de RMN (National NMR Network) in December 2006, and its installation completed in March 2007. The equipment, controlled via Topspin V.3.2 software installed on a PC with the LINUX operating system, comprises an AVANCE II+ double bay console and an 800 MHz compact Ultra-Shield-Plus Magnet with a 54 mm diameter bore. The 5 Gauss magnetic field safety line is described by an ellipsoid with a horizontal and vertical radius of 1.5 m and 2.5 m, respectively, from the magnetic center.

Along 2019 the spectrometer was upgraded with the installation of a cold 24 positions SampleCase (autosampler) and a CP2.1 TCI-z H&F/C/N 5 mm inverse detection probe-head with actively cooled preamplifier electronics.

Table of sensitivities (signal to noise ratios) for HR probe-heads:

CP2.1 TCI-z H&F/C/N

The CP2.1 TCI-z H&F/C/N-D (5 mm) is a probe-head with inverse detection and actively cooled preamplifier electronics (optimized for ¹H observing), designed to operate at three fixed frequencies (¹H, ¹³C and ¹⁵N), also with the possibility of ¹⁹F direct observation without 1H decoupling, with pulse-field gradients along Z axis and automatically tunable. This probe-head allows the acquisition of multi-dimensional triple resonance spectra from triple-labelled protein samples as well as less complex data from double- single- or non-labelled samples.

It is also possible to perform D decoupling using the deuterium channel from the lock system, together with the other three specific nuclei, allowing the decoupling up to four nuclei in only one pulse sequence.

Minimum sample volume: 500 ul
Working temperature range: +80 to -40ºC
Purchase date: 2019

QXI-z H-C/N/P

The QXI-z H-C/N/P-D (5mm) is a probe-head with inverse detection (optimized for ¹H observing), designed to operate at four fixed frequencies (¹H, ¹³C, ¹⁵N and ³¹P), with pulse-field gradients along Z axis and automatically tunable. This probe-head allows the acquisition of multi-dimensional triple resonance spectra from triple-labelled protein samples as well as less complex data from double- single- or non-labelled samples. In addition, the presence of a ³¹P channel allows the acquisition of multi-dimensional correlation data from phosphorylated compounds containing samples.

It is also possible to perform D decoupling using the deuterium channel from the lock system, together with the other three specific nuclei, allowing the decoupling up to four nuclei in only one pulse sequence.

Minimum sample volume: 500 ul
Working temperature range: +150 to -150ºC
Purchase date: 2007

TXI-z H-C/N

The TXI-z HH-C/N-D (5mm) is a probe-head with inverse detection (optimized for ¹H observing), designed to operate at three fixed frequencies (¹H, ¹³C and ¹⁵N), with pulse-field gradients along Z axis and automatically tunable. This probe-head allows the acquisition of multi-dimensional double resonance spectra from double-labelled protein samples as well as less complex data from single- or non-labelled samples. The tune/match range was modified by the manufacturer in order to deal with high salinity samples, like intracellular extracts, and allowing the best performances during structural analysis of low molecular weight compounds proceeding from metabolomics.

It is also possible to perform D decoupling using the deuterium channel from the lock system, together with the other two specific nuclei, allowing the decoupling up to three nuclei in only one pulse sequence.

Minimum sample volume: 500 ul
Working temperature range: +150 to -150ºC
Purchase date: 2007

BBI-z H-X

The BBI-z H-X-D (5mm) is a probe-head with inverse detection (optimized for ¹H observing) and wide range frequency decoupling possibility (from ³¹P to ¹⁰⁹Ag), with pulse-field gradients along Z axis and automatically tunable. It can be used for structural studies based on homonuclear (e.g., COSY, NOESY, TOCSY, etc.) or heteronuclear (e.g., HSQC, HMQC, HMBC, etc.) correlations and their combined forms. Also, this probe-head is frequently used for ¹H-NMR experiments requiring heteronuclear decoupling and/or solvent suppression.

It is also possible to perform D decoupling using the deuterium channel from the lock system, together with a specific nucleus, allowing the decoupling of two nuclei in only one pulse sequence.

Minimum sample volume: 500 ul

Working temperature range: +150 a -150ºC
Purchase date: 2007

BBO-z X-H

The BBO-z X-H-D (5mm) is a wide frequency range direct observing (from ³¹P to ¹⁵N) and ¹H decoupling probe-head, equipped with pulse-field gradients along Z axis and automatically tunable. Being optimized for X nuclei direct observation, it can lead to excellent results when studying compounds containing low natural abundance nuclei such as ¹³C, ²⁹Si, ⁷⁷Se, ^119/117Sn, ^111/113Cd, ¹⁸⁵Re, etc.

Minimum sample volume: 500 ul

Working temperature range: +180 a -150ºC
Purchase date: 2007

QNP C/N/P-H

The QNP C/N/P-H-D (10mm) is a quadruple probe-head designed for direct observation of three fixed X nuclei frequencies (¹³C, ¹⁵N and ³¹P) and ¹H decoupling if applicable. The possibility to accommodate 10mm NMR tubes allows performing in vivo NMR studies using cellular suspensions, small organs, etc. The probe-head is equipped with a pneumatic switching accessory for automatic changing of observed NMR frequency.

Minimum sample volume: 2.5 ml
Working temperature range: +150 a -130ºC
Purchase date: 2006