The beta-galactoside-binding proteins galectin-1 and -3 are thought to modulate cell-extracellular matrix interactions in cell adhesion and migration. In this study, their occurrence in human trophoblast has been investigated. In the first trimester placenta galectin-1 is expressed in the cytotrophoblast of the mid and distal cell columns, but absent from the villous and proximal column cytotrophoblast. The villous syncytiotrophoblast was also positive. Galectin-3, on the other hand, was uniformly localized in the villous cytotrophoblast and mid and distal cell columns. Immunolocalization of these proteins in placental bed tissue has shown that galectin-1 and -3 are not present in cytokeratin-positive interstitially migrating cytotrophoblast. The co-localization of galectin-1 with extracellular laminin in cultures of cytotrophoblast, choriocarcinoma or decidual stromal cells is consistent with a role in the organization of extracellular matrix and the regulation of cell motility.

No abstract

This investigation included the determination of Na, K, Ca, Mg and Zn in lens and aqueous humor of cataract patients. Along with the development of senile cataract the Na concentration increased, while the K concentration diminished. In the cataractous eye lenses the concentration of Ca and Zn were higher than in normal transparent lenses. The concentrations of the investigated elements, except for Zn, were higher in lenses than in aqueous humor of the same patients. The concentration of Na and Zn in aqueous humor decreased as compared to the values for normal healthy persons. The Ca and K concentrations in aqueous humor were similar to the values for healthy persons. Investigations of electrolyte composition of the lens would be valuable for understanding the genesis and developmental mechanism of senile cataract.

A new lectin has been isolated from the coral Gerardia savaglia by affinity chromatography, using locust gum as an absorbent, and d‐mannose as eluant. Final purification was achieved by Bio‐Gel P300 gel filtration. The agglutinin is a protein composed of two polypeptide chains with a Mr of 14800; the two subunits are not linked by disulfide bond(s). The isoelectric point is 4.8, the amino acid composition is rich in the acidic amino acids aspartic acid and glutamic acid. The absorption maximum for the protein was at 276 nm; with a molar absorption coefficient of 1.27 × 105 M−1 cm−1. The lectin precipitated erythrocytes from humans (A, B and O), sheep, rabbit and carp with a titer between 25 and 1010; the affinity constant for lectin binding to sheep red blood cells was 2.8 × 108 M−1 and the number of binding sites, 3.2 × 105/cell. Ca2+ ions are required for full activity; the pH optimum lies in the range between 6 and 11. Inhibition experiments revealed that the lectin is specific for d‐mannose. The lectin is mitogenic only for those spleen lymphocytes from mice which had been activated by lipopolysaccharide. An interesting feature of this lectin is its ability to bind to glycoproteins present in nuclei from CV‐1 monkey kidney cells. The fluorescein‐isothiocyanate‐labelled lectin reacted with six polypeptides in the nuclear envelope from rat liver (Mr 190000, 115000, 80000, 62000, 56000 and 42000) and with two polypeptides in the nuclear matrix or pore complex lamina fraction (Mr 190000 and 62000). The lectin inhibited the nuclear envelope mRNA translocation system in vitro. It is suggested that this effect is due to an interaction of the lectin with the nuclear glycoproteins gp190 and/or gp62.

A soluble carbohydrate-binding protein with galactoside-binding properties (CBP14) was isolated from liver nuclei of adult rats. Proteins were extracted from membrane-depleted nuclei; they contained 3 major fractions (M_r 43,000, 14,000 and 10,000) which reacted with antibodies raised against human placental β-galactoside-binding lectin (HP 14) as well as with asialofetuin (ASF). Enrichment (72- to 143-fold) of CBP14 was carried out by affinity chromatography, using anti-HP 14 antibodies and ASF as consequent ligands. CBP14 retained by affinity column chromatography was characterized by the molecular mass, haemagglutinating activity and immuno-chemical cross-reactivity. By fluorescence technique using fluorescein-labelled neoglycoprotein (carrying lactose) as a probe, lactose-binding protein(s), e.g. the CBP14 described here, can be detected in a homogeneous staining pattern within the entire nucleus of CV-1 cells in the stationary phase of the cells. In case of logarithmically proliferating cells the lactose-binding protein(s) are arranged in a spot-like pattern along the rims of the cell nuclei. The putative ligand for the CBP14 is associated with the nuclear surface, irrespective of the proliferation state of the cells.