» Articles » PMID: 38398620

Matrix Selection Strategies for MALDI-TOF MS/MS Characterization of Cyclic Tetrapyrroles in Blood and Food Samples

Overview
Journal Molecules
Publisher MDPI
Specialty Biology
Date 2024 Feb 24
PMID 38398620
Authors
Affiliations
Soon will be listed here.
Abstract

Cyclic tetrapyrrole derivatives such as porphyrins, chlorins, corrins (compounds with a corrin core), and phthalocyanines are a family of molecules containing four pyrrole rings usually coordinating a metal ion (Mg, Cu, Fe, Zn, etc.). Here, we report the characterization of some representative cyclic tetrapyrrole derivatives by MALDI-ToF/ToF MS analyses, including heme b and c, phthalocyanines, and protoporphyrins after proper matrix selection. Both neutral and acidic matrices were evaluated to assess potential demetallation, adduct formation, and fragmentation. While chlorophylls exhibited magnesium demetallation in acidic matrices, cyclic tetrapyrroles with Fe, Zn, Co, Cu, or Ni remained steadfast against demetallation across all conditions. Phthalocyanines and protoporphyrins were also detectable without a matrix using laser desorption ionization (LDI); however, the incorporation of matrices achieved the highest ionization yield, enhanced sensitivity, and negligible fragmentation. Three standard proteins, i.e., myoglobin, hemoglobin, and cytochrome c, were analyzed either intact or enzymatically digested, yielding heme b and heme c ions along with accompanying peptides. Furthermore, we successfully detected and characterized heme b in real samples, including blood, bovine and cod liver, and mussel. As a result, MALDI MS/MS emerged as a powerful tool for straightforward cyclic tetrapyrrole identification, even in highly complex samples. Our work paves the way for a more comprehensive understanding of cyclic tetrapyrroles in biological and industrial settings, including the geochemical field, as these compounds are a source of significant geological and geochemical information in sediments and crude oils.

References
1.
Xing Y, Gao S, Zhang X, Zang J . Dietary Heme-Containing Proteins: Structures, Applications, and Challenges. Foods. 2022; 11(22). PMC: 9689966. DOI: 10.3390/foods11223594. View

2.
Chiavarino B, Crestoni M, Fornarini S, Rovira C . Protonated heme. Chemistry. 2006; 13(3):776-85. DOI: 10.1002/chem.200600748. View

3.
Huang S, Hung C, Wu W, Chen B . Determination of chlorophylls and their derivatives in Gynostemma pentaphyllum Makino by liquid chromatography-mass spectrometry. J Pharm Biomed Anal. 2008; 48(1):105-12. DOI: 10.1016/j.jpba.2008.05.009. View

4.
Pashynska V, Van den Heuvel H, Claeys M, Kosevich M . Characterization of noncovalent complexes of antimalarial agents of the artemisinin-type and FE(III)-heme by electrospray mass spectrometry and collisional activation tandem mass spectrometry. J Am Soc Mass Spectrom. 2004; 15(8):1181-90. DOI: 10.1016/j.jasms.2004.04.030. View

5.
Calvano C, Monopoli A, Cataldi T, Palmisano F . MALDI matrices for low molecular weight compounds: an endless story?. Anal Bioanal Chem. 2018; 410(17):4015-4038. DOI: 10.1007/s00216-018-1014-x. View