The peer-review of a scientific manuscript is not open. It occurs behind closed
doors. The referees and Editors of scientific journals thus decide in a highly intransparent
procedure, whether a manuscript is interesting enough and suitable for publication or not. The arguments
remain secret. Their
judgement is often biased by special interests, in particular off-main stream papers tend to be suppressed. The referee system
is easily corrupted to reduce critical discussions and to exclude competitors. A recent submission
to JCP was rejected, because we did not remove a critical discussion of related literature as requested. Once a paper has been published,
even if it is obviously wrong, it is considered as established truth, writing critical comments is tedious and
time consuming. One of my comments, concerning a basic mathematical error, was processed three times
against the vote of the authors by JCP, before it was published. JCP does not publish letters anymore. The alternative would be a system
of open reviews, practiced partially by PNAS, making it easier to get published, but at the same
time, Comments would be facilitated to initiate a scientific discussion.
The motivation of this Website is to document the unusually large number of scientifically questionable
papers in bio-neutron scattering, published in high ranking journals like PNAS, PRL, BJ.
Here I illustrate the idea of open critical reviews with published papers, where
the referee system has obviouly failed. As the victim of a citation blockade, I found it increasingly
difficult, to publish alternative and critical views in main stream journals.
Neutron scattering is an open access technique, which is provided by large scale
facilities such as the FRM 2 in Garching FRM2
Biological inelastic neutron scattering can yield information on hydrogen based protein structural fluctuations and hydration water on a pico
to nano-second time scale, comparable to the range covered by MD simulations.
Open access means
that people with interesting ideas can get beam time, without demonstrating, that their knowledge of the technique is sufficient
to perform such experiments. This aspect may account in part for the above mentioned deficiencies.
The field was initiated in 1989 by the "Nature Milestone" paper of Doster et al.
, "Dynamical transition of
myoglobin revealed by inelastic
neutron scattering". It was my second NS paper out of 100, the
first one was with Martin Karplus. It showed for the first time
wide temperature and frequency range spectra of a hydrated protein, combining data derived with two
spectrometers IN6 and IN13 at the ILL in Grenoble. A small fraction of this paper was devoted
to the Q and temperature dependence of elastic scattering
, displaying two "dynamical transitions" near 160 and 240 K. At the transition
temperature the relaxation times of protein motions overlap with the respective instrumental
During the next 30 years only the elastic section was picked up in 90 % of the citations, the
equally important inelastic component was largely ignored.
G. Zaccai had the "ingenious" idea to reduce
biodynamic neutron scattering to elastic scans. This approach can be justified for particular applications,
specially if the biological material is available only in minor quantities ERS2003
. From elastic scans a very useful molecular
quantity, the "mean square displacement"
can be deduced by fitting the data at low Q to straight lines.
This simple method convinced many biologists, experienced in static low angle scattering, to consider
The possibility to deduce "biological
dynamics" from elastic scattering experiments, boosted the field with a flood of publications. Not all of them
were of high quality.
To cite a paper without reading it completely can be dangerous. For the "dynamical transition"
the spectral analysis demonstrated that the nonlinear onset in the displacements at 240 K was resolution controlled.
Thus with their "elastic only analysis", a wide range of questionable interpretations was possible..
(1) Most important, the elastic scans had to cover a wide temperature range, far below room temperature to spot
the "dynamical transitions". To avoid ice formation, this required "hydrated" instead of solvated samples. The properties of solvents
at low temperatures can lead to strange effects of demixing, ice formation and glass transitions,
explaining some questionable interpretations. It was shown, that the "dynamical transition" can be recorded at room temperature
by the new technique of
"elastic resolution spectroscopy" with IN5 data, Doster et al. 2001
. Thus also the low temperature transition at 160 K
is resolution controlled and was assigned for the first time to methyl rotation.
(2) The restriction to the tiny elastic part of the spectrum near zero frequency,
ignoring the rest of the energy window, reflects essentially the immobile, structurally static property of the
biomolecule. Dynamics enters only via a diminishing elastic intensity with increasing temperature.
(3) Another problematic restriction is the focus on the narrow Q-range near zero momentum exchange, to derive mean square displacements,
assuming the "Gaussian approximation".
Several workers did not fully understand the limitations of their method, its dependence on instrumental
resolution and multiple scattering: The zero Q-extrapolated intensity decreases with increasing temperature.
The "factor of two problem" with the Gaussian Lamb-Mössbauer factor lead to a confusion about the correct magnitude of
mean square displacements Doster, EBJ 2008
The "elastic intensity" approach recieved its final approvement, when the prestigious "Walter Hälg" prize was devoted to G. Zaccai in 2013.
His publications provide very instructive examples of long lasting errors and sensational results.
In his Science 2000 paper he interpreted the protein dynamical transition as resilence softening of the
protein force constants. 13 years later at the "Les Houches School" , he presented the identical concept, although
is was disproven by us in 1989 and many times later. G. Zaccai, Les Houches 2013
. It was the main topic
of the laudatio for the prize given by J. Smith. The latter has published since 1990 a huge number of
MD-papers, advertising "dynamic heterogeneity", including the "dynamical transition in a dry protein" Liu et al., PRL 2017
Biomolecular neutron scattering recieved a serious blow, when the nuclear physicist Hans Frauenfelder
took control of the field beyond 2008, resulting in a dramatic decline of scientific quality.
Now, energy landscapes and motional heterogeneity became main stream to explain bioneutron scattering.
The complexity of dynamics, controlled by energy landscapes, naturally required the assistance
of computer simulation. Elastic neutron scattering experiments are only needed to confirm the time resolved
MD simulations. In his most recent papers (PNAS 2015/ 2017, discussed below) Frauenfelder suggests
a complete re-interpretation of quasi-elastic neutron
scattering theory in terms of inhomogeneous spectral broadening. Elastic scattering is dismissed. The hopping across an energy landscape is defined as the basic physical process in proteins.
Spatial displacements, defining the Van Hove space-time correlation
function, are replaced by diffusion in energy space.
Frauenfelder, PNAS 2014
The molecular view:
Our approach of discussing protein motions in terms of few well defined molecular components, standard in other fields (NMR), was
misquoted by the heterogeneity group as a two-state model. Already in 1989 we started with two dynamic components, rotational transitions and water-coupled translational
motions. Our new RT model describes wide range data successfully in the time domain without the need of low temperatures.
The "protein dynamical transition" is no longer present in this model, since the data were corrected for
the instrumental resolution.
It is revealing, that the respective manuscript, submitted to J. Chem. Phys. in 2018, with the provocative title, "Protein dynamics without energy landscape"
although the referees could not justify their verdict with decent scientific arguments.
One referee, who sounded a lot like Hans Frauenfelder, was completely opposed to the landscape-free model:
"not new", "self-citations". The second referee with MD background supported the publication, but requested to remove all critical comments to related work. This
was rejected by us, since the purpose of this manuscript was to present an alternative view to dynamic heterogeneity.
The Editors refused to involve a third referee, familiar with experimental neutron scattering.
At the ECNS 2019 in St. Petersburg, our submitted oral contribution, a compact version of the JCP manuscript,
was downgraded to the level of a Poster.
By contrast, the "elastic only scattering group" recieved several invited talks from the
organizers. One negative highlight was the dubious "water-protein decoupling" hypothesis of
A. Benedetto, based on Q-averaged elastic scattering data (Phys. Chem. Lett. 2017). But the most scandalous
talk was presented by Kearley and Benedetto on "Elastic Scattering Spectroscopy", which
is a downgraded copy of what we had initially published in 2001 under the close, more appropriate name
"Elastic Resolution Spectroscopy" (Doster
et al. Physica B, 2001). According to their paper, elastic scattering experiments at different resolution
are sufficient, after some numerical treatment, to determine the exact intermediate scattering function. This was
shown to be incorrect (Doster et al. JCP, 2013).
The citation blockade thus still exists, illustrating, why this Web Site is necessary.
Our new pedagogical
version of how elastic and inelastic scattering with proteins can be combined, including a discussion of protein function, was published in Doster, 2018
"Are proteins dynamically heterogeneous?".
The role of errors and critical Comments to selected literature:
Said a big shot in this field to a young professor, the names are known,"in your last
paper you said, I was wrong", "weren't you wrong?" "Yes, but you don't say it."
This Web site is going
to "say it". Hans Frauenfelder said to his postdoc: "Possibly I am wrong, but it will take them a long time to
find out". Errors,
according to Enrico Fermi,
are quite common in Science. What matters is, how fast you find out. The philosoper Karl Popper proved, that
Science proceeds essentially via disprove of errors and less by confirming results.
It is not the errors that strike me, it is their persistence and the political forces to prevent
To illustrate my point, I present below critical comments to selected publications, which contain "common"
scientific errors or suggest conclusions, which are not properly justified.
I emphasize, that this Web site reflects my personal view, which could be wrong, unjust or incomplete.
Of course, a lot of high quality work has been published in this field: The Berlin group around Jörg Fitter
and the late Rueb Lechner combined successfully elastic and inelastic experiments to study bacteriorhodopsin, still valid today.
Another landmark paper, covering the transition from powder to solution was published by J Pérez, JM Zanotti, D Durand,
Biophysical journal 77 (1), 454-469. Longeville and Stingaciu (2017) determine the role of hemoglobin diffusion inside blood cells to facilitate
oxygen exchange in the lung with NSE (Sci. Rep. 7: 10448). The Munich-Jülich NSE group studies the polymer properties of partially folded proteins in the time domain, which
has yielded interesting results.
Some rarely cited Doster papers: Lit.
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