Proteomics in Forensic Sciences: Identification of the Nature of the Last Meal at Autopsy

A long-term psychiatric 40 years-old male patient was found dead at 9:00 a.m. in the clinic where he lived. Death was caused by traumatic injuries, which the sanitary staff imputed to a fall. Nurses declared that the patient refused having breakfast, whereas at autopsy the stomach contained 350 g of whitish semifluid material. Using both shotgun and gel-based proteomics, we demonstrated that the chyme contained partly digested milk- and bread-derived proteins, eaten during a recent breakfast. The conflict between evidence and assertions of the attending sanitary staff prompted the Legal Authority to undertake detailed investigations to ascertain facts and possible responsibilities. The herein characterization provides insights in the in vivo mechanisms of gastric breakdown of food proteins in a real meal. β-lactoglobulin was partially resistant to gastric digestion as confirmed by Western blot analysis, in contrast to caseins and wheat gluten proteins, which had been degraded by gastric fluids. In addition to a complex pattern of gastric proteins (e.g., mucin-5AC, pepsin A-3, pepsinogen C, gastric lipase, gastrokine-2, trefoil factors), chyme contained intact proteins and variably sized food-derived polypeptides arising from peptic and nonpeptic proteolytic cleavage as well as heterodimeric disulfide-cross-linked peptides. These findings suggest that the current analytical workflows offer only a partial picture of the real complexity of the human “digestome”

Proteomics in Forensic Sciences: Identification of the Nature of the Last Meal at Autopsy

A long-term psychiatric 40 years-old male patient was found dead at 9:00 a.m. in the clinic where he lived. Death was caused by traumatic injuries, which the sanitary staff imputed to a fall. Nurses declared that the patient refused having breakfast, whereas at autopsy the stomach contained 350 g of whitish semifluid material. Using both shotgun and gel-based proteomics, we demonstrated that the chyme contained partly digested milk- and bread-derived proteins, eaten during a recent breakfast. The conflict between evidence and assertions of the attending sanitary staff prompted the Legal Authority to undertake detailed investigations to ascertain facts and possible responsibilities. The herein characterization provides insights in the in vivo mechanisms of gastric breakdown of food proteins in a real meal. β-lactoglobulin was partially resistant to gastric digestion as confirmed by Western blot analysis, in contrast to caseins and wheat gluten proteins, which had been degraded by gastric fluids. In addition to a complex pattern of gastric proteins (e.g., mucin-5AC, pepsin A-3, pepsinogen C, gastric lipase, gastrokine-2, trefoil factors), chyme contained intact proteins and variably sized food-derived polypeptides arising from peptic and nonpeptic proteolytic cleavage as well as heterodimeric disulfide-cross-linked peptides. These findings suggest that the current analytical workflows offer only a partial picture of the real complexity of the human “digestome”

Proteomics in Forensic Sciences: Identification of the Nature of the Last Meal at Autopsy

A long-term psychiatric 40 years-old male patient was found dead at 9:00 a.m. in the clinic where he lived. Death was caused by traumatic injuries, which the sanitary staff imputed to a fall. Nurses declared that the patient refused having breakfast, whereas at autopsy the stomach contained 350 g of whitish semifluid material. Using both shotgun and gel-based proteomics, we demonstrated that the chyme contained partly digested milk- and bread-derived proteins, eaten during a recent breakfast. The conflict between evidence and assertions of the attending sanitary staff prompted the Legal Authority to undertake detailed investigations to ascertain facts and possible responsibilities. The herein characterization provides insights in the in vivo mechanisms of gastric breakdown of food proteins in a real meal. β-lactoglobulin was partially resistant to gastric digestion as confirmed by Western blot analysis, in contrast to caseins and wheat gluten proteins, which had been degraded by gastric fluids. In addition to a complex pattern of gastric proteins (e.g., mucin-5AC, pepsin A-3, pepsinogen C, gastric lipase, gastrokine-2, trefoil factors), chyme contained intact proteins and variably sized food-derived polypeptides arising from peptic and nonpeptic proteolytic cleavage as well as heterodimeric disulfide-cross-linked peptides. These findings suggest that the current analytical workflows offer only a partial picture of the real complexity of the human “digestome”

Proteomics in Forensic Sciences: Identification of the Nature of the Last Meal at Autopsy

A long-term psychiatric 40 years-old male patient was found dead at 9:00 a.m. in the clinic where he lived. Death was caused by traumatic injuries, which the sanitary staff imputed to a fall. Nurses declared that the patient refused having breakfast, whereas at autopsy the stomach contained 350 g of whitish semifluid material. Using both shotgun and gel-based proteomics, we demonstrated that the chyme contained partly digested milk- and bread-derived proteins, eaten during a recent breakfast. The conflict between evidence and assertions of the attending sanitary staff prompted the Legal Authority to undertake detailed investigations to ascertain facts and possible responsibilities. The herein characterization provides insights in the in vivo mechanisms of gastric breakdown of food proteins in a real meal. β-lactoglobulin was partially resistant to gastric digestion as confirmed by Western blot analysis, in contrast to caseins and wheat gluten proteins, which had been degraded by gastric fluids. In addition to a complex pattern of gastric proteins (e.g., mucin-5AC, pepsin A-3, pepsinogen C, gastric lipase, gastrokine-2, trefoil factors), chyme contained intact proteins and variably sized food-derived polypeptides arising from peptic and nonpeptic proteolytic cleavage as well as heterodimeric disulfide-cross-linked peptides. These findings suggest that the current analytical workflows offer only a partial picture of the real complexity of the human “digestome”

Differential representation of liver proteins in obese human subjects suggests novel biomarkers and promising targets for drug development in obesity

<p>The proteome of liver biopsies from human obese (O) subjects has been compared to those of nonobese (NO) subjects using two-dimensional gel electrophoresis (2-DE). Differentially represented proteins were identified by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS)-based peptide mass fingerprinting (PMF) and nanoflow-liquid chromatography coupled to electrospray-tandem mass spectrometry (nLC-ESI-MS/MS). Overall, 61 gene products common to all of the liver biopsies were identified within 65 spots, among which 25 ones were differently represented between O and NO subjects. In particular, over-representation of short-chain acyl-CoA dehydrogenase, Δ(3,5)-Δ(2,4)dienoyl-CoA isomerase, acetyl-CoA acetyltransferase, glyoxylate reductase/hydroxypyruvate reductase, fructose-biphosphate aldolase B, peroxiredoxin I, protein DJ-1, catalase, α- and β-hemoglobin subunits, 3-mercaptopyruvate S-transferase, calreticulin, aminoacylase 1, phenazine biosynthesis-like domain-containing protein and a form of fatty acid-binding protein, together with downrepresentation of glutamate dehydrogenase, glutathione S-transferase A1, S-adenosylmethionine synthase 1A and a form of apolipoprotein A-I, was associated with the obesity condition. Some of these metabolic enzymes and antioxidant proteins have already been identified as putative diagnostic markers of liver dysfunction in animal models of steatosis or obesity, suggesting additional investigations on their role in these syndromes. Their differential representation in human liver was suggestive of their consideration as obesity human biomarkers and for the development of novel antiobesity drugs.</p

Cell growth and MDH activity of <i>L</i>. <i>reuteri</i> CRL 1101 grown in MRS_G and MRS_GF at 37°C for 24 h.

<p>a) Growth kinetics in both media; b) Specific MDH activity in both media; c, d) Carbohydrate consumption and mannitol production in MRS_G and MRS_GF, respectively. Statistical analysis in Fig 2b was performed using two-way ANOVA followed by Bonferroni post-test. A value of <i>p<</i>0.05 was considered statistically significant.</p

Conversion of fructose into mannitol catalyzed by the mannitol 2-dehydrogenase (MDH) enzyme.

<p>Conversion of fructose into mannitol catalyzed by the mannitol 2-dehydrogenase (MDH) enzyme.</p

Proteins of <i>Lactobacillus reuteri</i> CRL 1101 over-expressed or repressed at 8 h of incubation in the presence of fructose, separated by 2DE and identified by Maldi ToF–MS-MS.

<p>Proteins of <i>Lactobacillus reuteri</i> CRL 1101 over-expressed or repressed at 8 h of incubation in the presence of fructose, separated by 2DE and identified by Maldi ToF–MS-MS.</p

Proteins of <i>Lactobacillus reuteri</i> CRL 1101 over-expressed or repressed at 24 h of incubation in the presence of fructose, separated by 2DE and identified by MS.

<p>Proteins of <i>Lactobacillus reuteri</i> CRL 1101 over-expressed or repressed at 24 h of incubation in the presence of fructose, separated by 2DE and identified by MS.</p

C_T values of <i>mdh</i> and <i>pyrG</i> genes of <i>L</i>. <i>reuteri</i> CRL 1101 grown in CDM in absence and presence of fructose (CDM_G and CDM_GF) for 8 and 24 h.

<p>C_T values of <i>mdh</i> and <i>pyrG</i> genes of <i>L</i>. <i>reuteri</i> CRL 1101 grown in CDM in absence and presence of fructose (CDM_G and CDM_GF) for 8 and 24 h.</p