Functionalized NaA Nanozeolites Labeled with 224,225Ra for Targeted Alpha Therapy

The 223Ra, 224Ra, and 225Ra radioisotopes exhibit very attractive nuclear properties for application in radionuclide therapy. Unfortunately the lack of appropriate bifunctional ligand for radium is the reason why these radionuclides have not found application in receptor-targeted therapy. In the present work, the potential usefulness of the NaA nanozeolite as a carrier for radium radionuclides has been studied. 224Ra and 225Ra, a-particle emitting radionuclides, have been absorbed in the nanometer-sized NaA zeolite (30–70 nm) through simple ion exchange. 224,225Ra-nanozeolites exhibited very high stability in solutions containing physiological salt, EDTA, amino acids, and human serum. To make NaA nanozeolite particles dispersed in water their surface was modified with a silane coupling agent containing poly(ethylene glycol) molecules. This functionalization approach let us covalently attach a biomolecule to the NaA nanozeolite surface.JRC.E.5-Nuclear chemistr

Properties of Arabinogalactan Proteins (AGPs) in Apple (Malus × Domestica) Fruit at Different Stages of Ripening

Arabinogalactan proteins (AGPs) are constituents of the cell wall–plasma membrane continuum in fruit tissue. The aim of the study was to characterise AGPs contained in fruit by determination of their chemical structure and morphological properties. The results were obtained from in and ex situ investigations and a comparative analysis of AGPs present in Malus × domestica fruit at different stages of ripening from green fruit through the mature stage to over-ripening during fruit storage. The HPLC and colorimetric methods were used for analyses of the composition of monosaccharides and proteins in AGPs extracted from fruit. We have found that AGPs from fruit mainly consists of carbohydrate chains composed predominantly of arabinose, galactose, glucose, galacturonic acid, and xylose. The protein moiety accounts for 3.15–4.58%, which depends on the various phases of ripening. Taken together, our results show that the structural and morphological properties of AGPs and calcium concentration in AGPs are related to the progress of ripening, which is correlated with proper fruit cell wall assembly. In line with the existing knowledge, our data confirmed the typical carbohydrate composition of AGPs and may be the basis for studies regarding their presumed properties of binding calcium ions

A practical guide to in situ and ex situ characterisation of arabinogalactan proteins (AGPs) in fruits

Abstract Background Arabinogalactan proteins (AGPs) are plant cell components found in the extracellular matrix that play crucial roles in fruit growth and development. AGPs demonstrate structural diversity due to the presence of a protein domain and an expanded carbohydrate moiety. Considering their molecular structure, the modification of glycosylation is a primary factor contributing to the functional variety of AGPs. Main body Immunocytochemical methods are used for qualitative and quantitative analyses of AGPs in fruit tissues. These include in situ techniques such as immunofluorescence and immunogold labelling for visualising AGP distribution at different cellular levels and ex situ methods such as Western blotting and enzyme-linked immunoenzymatic assays (ELISA) for molecular characterisation and quantitative detection of isolated AGPs. The presented techniques were modified by considering the structure of AGPs and the changes that occur in fruit tissues during the development and ripening processes. These methods are based on antibodies that recognise carbohydrate chains, which are the only commercially available highly AGP-specific tools. These probes recognise AGP epitopes and identify structural modifications and changes in spatio-temporal distribution, shedding light on their functions in fruit. Conclusion This paper provides a concise overview of AGP research methods, emphasising their use in fruit tissue analysis and demonstrating the accessibility gaps in other tools used in such research (e.g. antibodies against protein moieties). It underscores fruit tissue as a valuable source of AGPs and emphasises the potential for future research to understand of AGP synthesis, degradation, and their roles in various physiological processes. Moreover, the application of advanced probes for AGP visualisation is a milestone in obtaining more detailed insights into the localisation and function of these proteins within fruit

Review: structure and modifications of arabinogalactan proteins (AGPs)

Abstract The aim of this report is to provide general information on the molecular structure and synthesis of arabinogalactan proteins (AGPs) in association to their physiological significance. Assessment of genetic modifications of the activity of enzymes involved in the AGP biosynthesis is an efficient tool to study AGP functions. Thus, P4H (prolyl 4 hydroxylase) mutants, GLCAT (β-glucuronosyltransferase) mutants, and GH43 (glycoside hydrolase family 43) mutants have been described. We focused on the overview of AGPs modifications observed at the molecular, cellular, and organ levels. Inhibition of the hydroxylation process results in an increase in the intensity of cell divisions and thus, has an impact on root system length and leaf area. In turn, overexpression of P4H genes stimulates the density of root hairs. A mutation in GLCAT genes responsible for the transfer of glucuronic acid to the AGP molecule revealed that the reduction of GlcA in AGP disrupts the substantial assembly of the primary cell wall. Furthermore, silencing of genes encoding GH43, which has the ability to hydrolyze the AGP glycan by removing incorrectly synthesized β-1,3-galactans, induces changes in the abundance of other cell wall constituents, which finally leads to root growth defects. This information provides insight into AGPs as a crucial players in the structural interactions present in the plant extracellular matrix

Calcium oxalate crystals in the stem of Sida hermaphrodita (L.) Rusby (Malvaceae)

Observations of calcium oxalate crystals of the stem of an energetic plant S. hermaphrodita (L.) Rusby from the Malvaceae family, were performed using LM, DIC, and CLSM microscopes. The transversal and longitudinal sections showed the presence of calcium oxalate crystals in the parenchymal tissue distributed in various layers of the stem. The crystals occurred only in the form of druses. In the innermost part of the stem, i.e. in the pith, the calcium oxalate crystals occurred singly in individual cells. In the parenchyma cells separating sclerenchyma fibres and adjacent to the xylem, the crystals were observed individually in single cells, but the cells containing druses formed rows consisting of even several cells. The cortex contained the different-size druses scattered randomly within the cells. Druses differ in shape and size but they do not protrude beyond the cells although they very often fill them completely. The functions of calcium oxalate crystals are discussed

Specific ultrastructure of the leaf mesophyll cells of Deschampsia antarctica Desv. (Poaceae)

The ultrastucture of mesophyll cells of Deschampsia antarctica Desv. (Poaceae) leaves was investigated using the standard method of preparing material for examination in transmission electron microscopy (TEM). The investigated leaves were collected from the Antarctic hairgrass growing in a tundra microhabitat and representing xermorphic morphological and anatomical features. The general anatomical features of mesophyll cells are similar to those in cells of another grass leaves. The observations of the ultrastructure of mesophyll cells have shown that the organelles are located close to each other in a relatively small amount of the cytoplasm or closely adhere to each other. Organelles such as mitochondria, peroxisomes, and Golgi apparatus, as well as osmiophilic materials are gathered close to the chloroplasts. The chloroplast of the mesophyll cells of the D. antarctica leaf can form concavities filled with the cytoplasm. Such behaviour and ultrastructure of organelles facilitate exchange/flow of different substances engaged in the metabolic activity of the cell between cooperating organelles.Przy użyciu standardowej metody przygotowywania materiału, badano ultrastrukturę komórek mezofilu liści Deschampsia antarctica Desv. (Poaceae) w mikroskopie elektronowym transmisyjnym (TEM). Badane liście zostały zebrane z okazów śmiałka antarktycznego rosnącego w mikrośrodowisku tundrowym, reprezentujących kseromorficzne cechy morfologiczne i anatomiczne. Ogólne cechy anatomiczne komórek mezofilu są podobne do komórek liści innych traw. Obserwacjeultrastruktury komórek wykazały, że organelle komórek mezofilowych występują blisko siebie w stosunkowo niewielkiej ilości cytoplazmy lub ściśle przylegają do siebie. Organelle takie jak mitochondria, peroksysomy, aparaty Golgiego, a także osmofilne materiały gromadzą się w pobliżu chloroplastów. Chloroplasty komórek mezofilu D. antarctica często mają wklęsłości wypełnione cytoplazmą. Takie zachowanie i budowa ultrastrukturalna organelli ułatwia wymianę/przepływ różnych substancji zaangażowanych w aktywność metaboliczną między współdziałającymi organellami komórki

Ultrastruktura komórek mezofilu liści Deschampsia antarctica Desv. (Poaceae)

The ultrastucture of mesophyll cells of Deschampsia antarctica Desv. (Poaceae) leaves was investigated using the standard method of preparing material for examination in transmission electron microscopy (TEM). The investigated leaves were collected from the Antarctic hairgrass growing in a tundra microhabitat and representing xermorphic morphological and anatomical features. The general anatomical features of mesophyll cells are similar to those in cells of another grass leaves. The observations of the ultrastructure of mesophyll cells have shown that the organelles are located close to each other in a relatively small amount of the cytoplasm or closely adhere to each other. Organelles such as mitochondria, peroxisomes, and Golgi apparatus, as well as osmiophilic materials are gathered close to the chloroplasts. The chloroplast of the mesophyll cells of the D. antarctica leaf can form concavities filled with the cytoplasm. Such behaviour and ultrastructure of organelles facilitate exchange/flow of different substances engaged in the metabolic activity of the cell between cooperating organelles.Przy użyciu standardowej metody przygotowywania materiału, badano ultrastrukturę komórek mezofilu liści Deschampsia antarctica Desv. (Poaceae) w mikroskopie elektronowym transmisyjnym (TEM). Badane liście zostały zebrane z okazów śmiałka antarktycznego rosnącego w mikrośrodowisku tundrowym, reprezentujących kseromorficzne cechy morfologiczne i anatomiczne. Ogólne cechy anatomiczne komórek mezofilu są podobne do komórek liści innych traw. Obserwacjeultrastruktury komórek wykazały, że organelle komórek mezofilowych występują blisko siebie w stosunkowo niewielkiej ilości cytoplazmy lub ściśle przylegają do siebie. Organelle takie jak mitochondria, peroksysomy, aparaty Golgiego, a także osmofilne materiały gromadzą się w pobliżu chloroplastów. Chloroplasty komórek mezofilu D. antarctica często mają wklęsłości wypełnione cytoplazmą. Takie zachowanie i budowa ultrastrukturalna organelli ułatwia wymianę/przepływ różnych substancji zaangażowanych w aktywność metaboliczną między współdziałającymi organellami komórki

Female sporogenesis in the native Antarctic grass Deschampsia antarctica Desv.

The development of megasporocytes and the functional megaspore formation in Deschampsia antarctica were analyzed with the use of microscopic methods. A single archesporial cell was formed directly under the epidermis in the micropylar region of the ovule without producing a parietal cell. In successive stages of development, the meiocyte was transformed into a megaspore tetrad after meiosis. Most megaspores were arranged in a linear fashion, but some tetrads were T-shaped. Only one of the 60 analyzed ovules contained a cell in the direct proximity of the megasporocyte, which could be an aposporous initial. Most of the evaluated D. antarctica ovules featured monosporic embryo sacs of the Polygonum type. Approximately 30% of ovules contained numerous megaspores that were enlarged. The megaspores were located at chalazal and micropylar poles, and some ovules featured two megaspores – terminal and medial – in the chalazal region, or even three megaspores at the chalazal pole. In those cases, the micropylar megaspore was significantly smaller than the remaining megaspores, and it did not have the characteristic features of functional megaspores. Meiocytes and megaspores of D. antarctica contained polysaccharides that were detectable by PAS-reaction and aniline blue staining. Starch granules and cell walls of megasporocytes, megaspores and nucellar cells were PAS-positive. Fluorescent callose deposits were identified in the micropylar end of the megasporocytes. During meiosis and after its completion, thick callose deposits were also visible in the periclinal walls and in a small amount in the anticlinal walls of megaspores forming linear and T-shaped tetrads. Callose deposits fluorescence was not observed in the walls of the nucellar cells