Proteomic studies of honeybee- and manually-collected pollen

Abstract

In this study a new approach to quantitative and qualitative proteomic evaluation of pollen of different botanical origin was proposed. A monofloral mixture of plum (Prunus) -86.83 ± 0.70% and willow (Salix spp.) -13.7 ± 0.30% pollen, and monofloral plum (Prunus) pollen collected by bees was studied. Other pollen was collected manually from pear (Pyrus communis), apple tree (Malus sylvestris), cherry (Prunus / Cerasus) and wild cherry (Prunus avium). Samples were made during an early spring plant blossom. Proteins isolated from pollen samples were fractionated by a two-dimensional electrophoresis (2-DE) and about 50 proteins were identified using mass spectrometry analysis. A three-dimensional (3-D) visualization of proteins was performed. The intensities of protein spots differed in the orchard pollen samples more than ten times. The biological functions of the identified proteins differ, i.e. they are involved in transcription / translation, metabolic and other cellular processes. The data revealed up-regulated process of the enzyme 5-methyltetrahydropteroyltriglutamate-homocysteine methyltransferase 1 in all pollen involved in methionine formation, which was the highest in monofloral orchard pollen collected by bees. This enzyme was identified in all the tested pollen. High level of expression of putative flavin-containing monooxygenase FMO GS-OX-like 11 protein was found in manually-collected pollen. This protein is important for plant protection against pathogens as well for plant hormone biosynthesis.

Polyphenol profile of buckwheat honey, nectar and pollen

“…Buckwheat honey is highly valued, with specific organoleptic properties, such as strong flavour, characteristic colour, pungent taste and aroma of molasses, but not preferred by consumers [3]. Regardless of estimation by consumers, buckwheat honey has a very high nutritional value with beneficial antioxidant [4,5] and anti-inflammatory effects [6]. As compared with other types of honey, buckwheat honey showed a higher content of minerals, sugars and phenolic compounds [7][8][9].…”

The Unique Protein Composition of Honey Revealed by Comprehensive Proteomic Analysis: Allergens, Venom-like Proteins, Antibacterial Properties, Royal Jelly Proteins, Serine Proteases, and Their Inhibitors

“…These results indicated that honeys contain honeybee αglucosidase HBG3 and α-amylase at relatively steady and high levels. In previous proteomic studies, Rossano et al 26 and Di Girolamo et al 27 identified α-glucosidase but not α-amylase; however, α-amylase was detected by LC-MS/MS in Borutinskaite et al 30 and Zhang et al 29 This difference can be explained by the lower abundance of α-amylase as indicated by the intensity and spectral counts reported in this study.…”

“…Despite the wide array of proteins identified compared to Rossano et al we were not able to detect profilin, superoxide dismutase, and apisimin. Furthermore, despite detailed analyses performed together with individual investigations of records in databases, we were also unable to match our results for some proteins to those reported in other studies. , Moreover, our manual verification of the A. mellifera -related proteins reported in Borutinskaite et al revealed that more proteins can be identified in buckwheat honey, but the proteins were denoted as uncharacterized (see Table ; proteins denoted with + in the column d Honey).…”

“…The honey descriptions indicate the prevailing plant source as determined by beekeepers; we also included the honey that received the prize for honey of the year in Czechia in 2017 and one honey from wild-occurring nonmanaged bees. In addition to the identification characteristics, we provide information on the proteins that were identified in previous studies in d honey, − e venom, − and f royal jelly, − the g proven allergens from the list of 12 recently listed Apis mellifera allergens in the WHO/IUIS, the h proteins that we determined as allergen analogues, and the i proteins for which we confirmed the presence of a signal peptide, which is indicative of secretion. Each positive match is indicated by ×.…”

“…In recent studies, Zhang et al and Borutinskaite et al reported identification of MRJPs 1–9, alpha-glucosidase, α-amylase, glucose oxidase, and uncharacterized protein LOC408608. The latter study, which analyzed buckwheat honey, identified additional proteins such as transferrin 1, glucosylceramidase-like protein, and putative glucosylceramidase 4, and the authors reported additional proteins that were denoted as uncharacterized (see Table in this study). Interestingly, Azevedo et al aimed to discriminate among honeys using 2D-E proteomics.…”