RE: AMMRL: BioPack gNcpmgex_NH experiment

From: hsin <hsin.wang_at_sci.ccny.cuny.edu>
Date: Tue, 7 Jan 2014 14:14:02 -0500

Kirk,

I have a file that was done last year with gNcpmgex_NH and it had plenty of
signal, even after time_T2=60msec (my protein was not large).

I think Eugene is right about the gradients. In the original version, it
was clear the hypercomplex data were acquired by gradient selection using
icosel, where gzlvl8 and gzlvl11 were the pair. In the Biopack version,
they did not code it with icosel, but it may still be gradient selection by
the same pair. Had it adhered to Biopack convention, this pair would have
been gzlvl1 and gzlvl2, where gzlvl8 is halved because of the doubling of
g8. I think you may be able to verify this by arraying gzlvl11 in the
appropriate region. My gzlvl5 was 0, and that was probably default, and not
important.

Hsin

--
Hsin Wang, Ph. D.
NMR Facility Manager
City College of New York, CUNY
Marshak-1217
160 Convent Ave.
New York, NY 10031
212-650-5831 (phone)
212-650-8719 (fax)
> -----Original Message-----
> From: DeRose, Eugene (NIH/NIEHS) [C] [mailto:derose_at_niehs.nih.gov]
> Sent: Monday, January 06, 2014 1:34 PM
> To: Kirk Marat; ammrl_at_ammrl.org
> Subject: Re: AMMRL: BioPack gNcpmgex_NH experiment
> 
> Hi Kirk,
> 
> This experiment was originally written by Frans Mulder in Lewis Kay's
> group.  Upon comparing the parameters from the original experiment
> (N15_CPMG_Rex_NH2_fm_500_v2) with the BioPack parameters, I noticed
> that
> the gradient levels gzlvl5, gzlvl8 and gzlvl11 do not agree.  The
> correct
> values from the original experiment should be gzlvl5=-6000,
> gzlvl8=15000,
> and gzlvl11=29400.  I hope this helps.
> 
> Best regards,
> Eugene
> 
> Eugene DeRose, Ph.D.
> NIEHS NMR Laboratory Manager
> Contractor to NIEHS/DIR
> 919.541.1981
> derose_at_niehs.nih.gov
> 
> 
> 
> On 1/3/14 4:25 PM, "Kirk Marat" <Kirk.Marat_at_umanitoba.ca> wrote:
> 
> >Happy New Year everyone.
> >
> >Has anyone had any experience with the N15 T2 exchange experiment
> >(gNcpmgex_NH) in BioPack?  We can't seem to get it to work or even see
> >any signal in the first increment, even when the number of CPMG cycles
> is
> >very low.  Other BioPack sequences seem to work fine, suggesting that
> the
> >probe calibration file is fine.  Checking on the SPINSIGHTS site, it
> >appears that at least one other person has had trouble with this
> >experiment (in both VJ 3.2 and 4), but there was no real fix that I
> could
> >see.
> >
> >This is an INOVA600 running VnmrJ 3.2A.
> >
> >Thanks!
> >Kirk
> >
> >Kirk Marat, Ph. D.  NMR Facility Manager
> >Dept. of Chemistry, University of Manitoba
> >Winnipeg, Manitoba
> >R3T 2N2, Canada
> >
> >Ph: (204) 474-6259    FAX: (204) 474-7608
> >
> >

Received on Tue Jan 07 2014 - 09:14:07 MST