ISSN: 7027-2221

Keywords : Carboxypeptidase


The employment of MALDI-ToF in the chemical analysis of fingermarks.

Zaid Al-Obaidi; Simona Francese

karbala journal of pharmaceutical sciences, Volume 8, Issue 13, Pages 79-105

Background and objectives: Many endogenous and exogenous molecules with different chemical nature including lipids, vitamins, amino acids polymers and other small molecules have been detected by Matrix¬assisted laser desorption/ionization (MALDI). Many studies were done to detect proteins in body fluids; however, few focused on detecting proteins in sweat. Recently peptides and small proteins in finger marks were detected in laboratory experiments including dermcidin and dermcidin-derived peptides. The aim of this study is to confirm the identity of dermcidin and other peptide species that can be found within fingermarks.
Methodology: This study was performed with the employment of MALDI following two constitutive enzymatic digestions by trypsin and carboxypeptidase respectively. Bioinformatics tools were employed to identify and verify peptide maps. This work is important to both forensic and biomedical science fields. These sciences are interested in dermcidin and dermcidin-derived peptides. Also this study established the protocols with a high potential for many other detectable peptides.
Results: In this work, the detection and identification of dermcidin and dermcidin-derived molecules and possibly dual specificity phosphatase (DUSP27_ HUMAN, formerly known as DUPD1) has been achieved. This has been done by using enzymatic digestions while the expected fragments obtained with MALDI and confirmed by the employment of bioinformatics tools.
Discussion and Conclusions: The species of dermcidin and dermcidin tryptic digested peptides have been successfully identified directly in fingermark. Extra efforts are recommended to identify and confirm other peptides detected in fingermarks.