Long bones protein can reveal how long the body has been underwater.

1. BONE PROTEOMICS COULD REVEAL HOW
LONG A CORPSE HAS BEEN UNDERWATER
ATUL ABHISHEK

2. Introduction
If foul play was involved, a reliable estimation when someone
died can help investigators better understand what happened
to the person and can help them identify potential alleged
murders.
Estimate the time of death when a body found underwater isEstimate the time of death when a body found underwater is
very difficult because we can’t get valid data of algor mortis,
rigor mortis, insects life cycle.
One approach is to analyze the decomposition stage of many
body areas, but factors such as water salinity, depth, tides,
temperature, bacteria presence, and scavengers can make it
difficult to estimate PMI.

3. “The bones are stronger than the soft tissues, and they lie deep
within the body, so some of these effects can shield the
proteins within them” taking this concept Northumbria
University professor Noemi Procopio and colleagues have
applied the principles of forensic proteomics to the estimationapplied the principles of forensic proteomics to the estimation
of postmortem submerged interval (PMSI) in aquatic
environments.

4. Experimental process
For testing a hypothesis Noemi Procopio and colleagues take
a mouse's corpse in underwater, and also taken different types
of water mattered .
tap water,
saltwater,saltwater,
pond water
chlorinated water.
After a 1 or 3 weeks of PMSI , the team collected the tibia, or lower leg
bones, from the corpses, extracted the top 30 proteins and analyzed them
by mass spectrometry. The proteins clustered according to their PMSI, and
there was a clear distinction between the 1-week cluster, the 3-week cluster
and the controls.
The researchers found that the time since submersion had a greater effect
on protein levels than the different types of water.

5. According to the study results, the 1-week cluster was
characterized by a higher abundance of bone-specific and
serum proteins. The researchers say this is because ubiquitous
and water-soluble proteins are released from the body first,
leaving an abundance of proteins in the first few days ofleaving an abundance of proteins in the first few days of
decomposition. After 3 weeks, however, muscle protein
finally decays and there is a noticeable reduction.
Only one protein was found to be significantly more abundant
in the controls than in any of the water environments, leading
the researchers to conclude PMSI is a much more important
variable than type of water.

6. “Despite the fact that different types of water have been
shown to alter the decomposition rate, proteins in bones are
quite ‘protected’ by the mineral matrix itself”, Procopio
told “This is the same reason why proteins can be
recovered from very old bone specimens, such as
archaeological ones, and are better preserved than
DNA. The fact that different types of water didn’t affect
archaeological ones, and are better preserved than
DNA. The fact that different types of water didn’t affect
the proteomic composition encourages us to proceed in
this direction.”

7. Diagrammatic representation of
experimentation
Source: https://dx.doi.org/10.1021/acs.jproteome.0c00060

8. Experimental result
Results showed that increasing PMSIs can influence the protein
abundances more than the different types of water.
In particular, the abundance of the muscle protein fructose-bisphosphate
aldolase A constantly decreased with increasing PMSIs.
The protein peptidyl-prolyl cis-trans isomerase showed a significant
decrease between controls and aquatic environments.
The coagulation factor VII was deamidated only in submerged samples
and not in terrestrial controls.
Fetuin-A was significantly more deamidated in pond water compared to
the other aquatic environments.

9. Conclusion
The study of long bone protein (peptides)
identication may have the potential to become
new biomarkers for :-
the identication of specic postmortemthe identication of specic postmortem
circumstances
the estimation of the PMSI
the characterization of the type of water involved
in criminal investigations.

10. References
Mizukami, H., Hathway, B., & Procopio, N. (2020). Aquatic
Decomposition of Mammalian Corpses: A Forensic
Proteomic Approach. Journal of Proteome Research, 19(5),
2122-2135. doi:10.1021/acs.jproteome.0c00060
Bone proteomics could reveal how long a corpse has beenBone proteomics could reveal how long a corpse has been
underwater. (2020, April 29). Retrieved October 7, 2020,
from
https://www.sciencedaily.com/releases/2020/04/2004291059
16.htm

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