Detection of honeybee venom in envenomed tissues by direct MALDI MSI

Abstract

A new analytical approach using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) for the study of honeybee venom is shown. In vitro and in vivo models simulating the bee sting have been developed using live honeybees and, as the envenomation sites, pig ears and rat legs; MALDI MSI has been used to map, over time, the diffusion and distribution of three venom allergens (Api m 1, Api m 4, and Api m 6) and two venom toxins (apamine and mast cell degranulating peptide). In conjunction with other classical biochemical techniques and high resolution mass spectrometry (HRMS), structural data have been obtained that contribute to current understanding of honeybee venom composition. Initial data have also been obtained demonstrating the feasibility of mapping the organism's response to the sting. The opportunity to monitor venom diffusion and the organism's response at the same time might open new pathways for in vivo preclinical studies in designing and testing new venom immunotherapy (VIT). (J Am Soc Mass Spectrom 2009, 20, 112-123)

Two-Step Matrix Application for the Enhancement and Imaging of Latent Fingermarks

“…In terms of sample pretreatment, when performing imaging experiments targeting proteins, immersion techniques involving dipping the mounted section in a bath of matrix solution prior to matrix deposition have been observed to increase the signal without delocalizing the analyte. 7,8 Independently from the mode of application, the most widely used deposition methods involve the use of "wet" matrix, i.e., ABSTRACT: Matrix deposition is a crucial aspect for successful matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI MSI) analysis. The search for more efficient protocols over the years has resulted in the devising of "dry matrix methods" in which the matrix is solely or preliminarily deposited as powder and acts in most cases as a seeding agent.…”

“…In terms of sample pretreatment, when performing imaging experiments targeting proteins, immersion techniques involving dipping the mounted section in a bath of matrix solution prior to matrix deposition have been observed to increase the signal without delocalizing the analyte. 7,8 Independently from the mode of application, the most widely used deposition methods involve the use of "wet" matrix, i.e., dissolved in an appropriate solvent combination prior to deposition. Sugiura et al used this principle in a two-step procedure to deposit matrix over a tissue section.…”

Shotgun proteome analysis of honeybee venom using targeted enrichment strategies

“…Overcoming the pitfalls of the classical two-dimensional electrophoresis approach conducted prior to mass spectrometric analysis allowed to develop a novel approach that is easier to handle. The gelfree shotgun proteomic strategy and sophisticated instrumentation led to a significant increase of the sensitivity and higher number of identified honeybee venom components, comparing with literature (Baracchi and Turillazzi, 2010;Francese et al, 2009;Matysiak et al, 2011b;Peiren et al, 2008). In the first part of this study Prespotted AnchorChip (PAC) targets were used (with HCCA matrix).…”

Diagnosis and treatment of allergy to hymenoptera venoms

“…A matrix-assisted laser desorption/ionization mass spectrometry imaging system has been experimentally used to map the diffusion and distribution of Api m 1, 4 and 6 allergens and two venom toxins (apamine and mast cell degranulating peptide) following envenomation of various tissues by live honeybees [13 ]. This procedure may provide a novel manner for studying the rate of absorption, thus facilitating the optimization of venom administration strategies during immunotherapy.…”