title: Postmortem degradation of skeletal muscle proteins: a novel approach to determine the time since death.
abstract: Estimating the time since death is a very important aspect in forensic sciences which is pursued by a variety of methods. The most precise method to determine the postmortem interval (PMI) is the temperature method which is based on the decrease of the body core temperature from 37 °C. However, this method is only useful in the early postmortem phase (~0-36 h). The aim of the present work is to develop an accurate method for PMI determination beyond this present limit. For this purpose, we used sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), Western blotting, and casein zymography to analyze the time course of degradation of selected proteins and calpain activity in porcine biceps femoris muscle until 240 h postmortem (hpm). Our results demonstrate that titin, nebulin, desmin, cardiac troponin T, and SERCA1 degraded in a regular and predictable fashion in all samples investigated. Similarly, both the native calpain 1 and calpain 2 bands disintegrate into two bands subsequently. This degradation behavior identifies muscular proteins and enzymes as promising substrates for future molecular-based PMI determination technologies.
authors.affiliation: Department of Cell Biology, University of Salzburg, Hellbrunnerstr. 34, 5020, Salzburg, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Pittner
authors.affiliation: Department of Forensic Medicine and Forensic Neuropsychiatry, University of Salzburg, Ignaz-Harrer-Straße 79, 5020, Salzburg, Austria.
authors.forename: Fabio C
authors.initials: FC
authors.lastname: Monticelli
authors.affiliation: Department of Cell Biology, University of Salzburg, Hellbrunnerstr. 34, 5020, Salzburg, Austria.
authors.forename: Alexander
authors.initials: A
authors.lastname: Pfisterer
authors.affiliation: Department of Cell Biology, University of Salzburg, Hellbrunnerstr. 34, 5020, Salzburg, Austria.
authors.forename: Angela
authors.initials: A
authors.lastname: Zissler
authors.affiliation: Department of Cell Biology, University of Salzburg, Hellbrunnerstr. 34, 5020, Salzburg, Austria.
authors.forename: Alexandra M
authors.initials: AM
authors.lastname: Sänger
authors.affiliation: Department of Cell Biology, University of Salzburg, Hellbrunnerstr. 34, 5020, Salzburg, Austria.
authors.forename: Walter
authors.initials: W
authors.lastname: Stoiber
authors.affiliation: Department of Cell Biology, University of Salzburg, Hellbrunnerstr. 34, 5020, Salzburg, Austria. peter.steinbacher@sbg.ac.at.
authors.forename: Peter
authors.initials: P
authors.lastname: Steinbacher
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002154:Calpain / Q000378:metabolism; D064211:Connectin / Q000378:metabolism; D003893:Desmin / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D049429:Forensic Pathology; D023421:Models, Animal; D009124:Muscle Proteins / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism*; D011180:Postmortem Changes; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000378:metabolism; D013552:Swine; D020107:Troponin T / Q000378:metabolism
chemical_list: D064211:Connectin; D003893:Desmin; D009124:Muscle Proteins; D020107:Troponin T; C035620:nebulin; D002154:Calpain; C484806:CAPN1 protein, human; C569870:CAPN2 protein, human; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; C506943:ATP2A1 protein, human
keywords: Degradation; Pig; Postmortem interval (PMI); Protein; Skeletal muscle