Occurrence of a blood group A-like substance in eggs of the prosobranch snail Pomacea canaliculata.

In the eggs of the prosobranch snails Pomacea canaliculata and Pomacea insularum a blood group A-like substance has been detected by anti-A from the snails Helix pomatia, Helix aspersa and Cepaea nemoralis.

Different glycosubstances and galactans in the albumin gland and eggs of Achatina fulica.

In saline extracts from the eggs and the albumin gland of the snail Achatina fulica 3 different forms of glycosubstances have been found by using heterophile precipitins from different sources: 1. An alkali-stable galactan reacting with the anti-galactans from Axinella polypoides sponge and from the clam Tridacna maxima (Tridacnin) and with Concanavalin A. 2. Another glycosubstance giving cross-reactions with a second precipitin from Axinella polypoides, with the lectin from Ricinus communis, with murine myeloma anti-galactan, with pneumococcus Type XIV antiserum and with Tridacnin. 3. The second precipitin from Axinella polypoides detects a third glycosubstance, which reacts with the lectins from Abrus precatorius and wheat germ (Triticum vulgaris).

Demonstration of organ-characteristic glycoproteins in human semen.

Tridacnin M, a galactosyl-specific reagent prepared from the bivalve clam Tridacna maxima (Röding) was used for the demonstration of 2 different glycosubstances with terminal galactosido units in human semen. The results obtained by immunodiffusion tests indicate that the seminal plasma contains a water-soluble glycoprotein with two carbohydrate chains, one of them having a terminal beta-galatosyl group whereas the other one seems to have a terminal N-acetyl-neuraminic acid group and a subterminal beta-galactosyl group. This glycoprotein is a secretion product of the seminal vesicles and, therefore, of diagnostic significance: it is absent in cases of bilateral occlusion of the ampullae. Another glycosubstance with terminal galactosido-residues could be demonstrated on the surface of sperm cells by agglutination reactions. This glycosubstance is an integral part of the spermatozoan membrane because it cannot be removed by repeated washings.

A new marker for neuraminidase-treated human serum glycoproteins from the haemolymph of Tridacna maxima (Röding).

Highly purified human serum glycoproteins were treated with neuraminidase. The exposed subterminal carbohydrate structures reacted strongly with an anti-galactan precipitin from the haemolymph of Tridacna maxima which detects terminal, non-reducing beta-D-galactoside residues. This invertebrate precipitin, Tridacnin, may be used as a marker for nearly two thirds of all asialo serum glycoproteins; A number of different cross-reactions with various other polysaccharides and galactans subdivides those neuraminidase-treated glycoproteins into several subgroups, indicating that the uncovered carbohydrate structures are not always completely identical. In this way, together with the cross-reacting precipitins from plant and invertebrate origin. Tridacnin may be a useful tool for elucidating and establishing the structure of the carbohydrate part of serum glycoproteins.

Anti-carbohydrate precipitins and haemagglutinins in haemolymph from Tridacna maxima (Röding).

Haemolymph from the elongate clam, Tridacna maxima (Röding) readily precipitates with H-blood group substances, pneumococcus type XIV polysaccharide, human milk and salivas, and with a number of polysaccharides which contain the O-SS-D-galactopyranosyl-(1-6)-D-galactose structure. Precipitation has been demonstrated using both gel diffusion and quantitative precipitin methods. T. maxima haemolymph strongly agglutinates human erythrocytes and haemagglutination can be inhibited by the same preparations which precipitate with the clam extract. Precipitins and haemagglutinins are inhibited by N-acetyl-D-galactosamine and by D-galactose residues preferably in ss-linkage. After agar gel immunoelectrophoresis at pH 8.6, T. maxima precipitin arcs are found in the alpha-region. Precipitation and inhibition results suggest that T. maxima extract and purified precipitin, may find widespread application in the study of many biologically important carbohydrates and glycoproteins.

Galactans and anti-galactans from invertebrates.

Antibody-like substances with anti-carbohydrate specificities directed against different structures of galactans have been detected in several invertebrates.

New lectin receptors in carcinoembryonic antigen (CEA).

The glycoprotein CEA (carcinoembryonic antigen) carries carbohydrate groups, which react with the plant lectins from Agaricus bisporus, Arachis hypogaea (peanut), with Tridacnin from invertebrate clams and with the anti-A lectins from snails. Accordingly, it has cryptantigenic structures, which correspond to the T or T-like antigen, the Tridacnin receptor and to the so called A-like antigen.

Tridacnin, a new mitogenic lectin from invertebrate sources.

A new group of invertebrate lectins with anti-beta-galactosyl specificity, the so-called Tridacnins from the Tridacnid bivalve clams have been found to show not only agglutinating and precipitating properties, but also mitogenic activity as tested with human lymphocytes.

[Serum cholinesterase as a model glycoprotein (author's transl)]. / Serumcholinesterase als Modell eines Glykoproteins.

Human serum cholinesterase (EC 3.1.1.8) is a carbohydrate-rich glycoprotein, which reacts with 18 different lectins from plants and invertebrates by a specific precipitin reaction; most of the lectins combine with alkali-stable bound carbohydrate chains. One third of these lectin receptors appear after neuraminidase-treatment, two thirds can be demonstrated before and after removal of neuraminic acid. The specific lectin receptors of the alkali-labile carbohydrate chains are characterized and analyzed by chemical and serological methods.

PCR-based detection of chlamydial infection in swine and subsequent PCR-coupled genotyping of chlamydial omp1-gene amplicons by DNA-hybridization, RFLP-analysis, and nucleotide sequence analysis.

Lung and intestine of 49 pigs with respiratory diseases and endocervical swabs from 205 sows with reproductive disorders were investigated for chlamydial infection by polymerase chain reaction. PCR primers targeted DNA sequences on the chlamydial omp1 or omp2 genes. PCR amplicons were generated from 49.0% of pigs with respiratory disease, from 60.0% of sows with reproductive disorders, from 24.5% of respiratory healthy controls, but from no endocervical swabs from fertile sows. By DNA hybridization, a high prevalence of mixed infections with Chlamydophila abortus and Chlamydia suis in the porcine lung and intestine was found and confirmed by RFLP and nucleotide analysis. Of the omp1-PCR amplicons from endocervical swabs 81.3% were identified as Chlamydophila abortus, indicating an association of this chlamydial species with reproductive disorders in sows. Nucleotide sequence analysis of omp1-amplicons identified as deriving from Chlamydia suis shared a maximum of 82.7% homology with the reference strain S45.

Blood group H like activity in crude preparations of bovine lung galactan.

In crude preparations of bovine lung galactan blood group H-like activity, which does not occur on bovine red cells, has been detected with heterophile anti-H-like reagents from different origin. These H-like receptors, associated with pneumococcus type XIV cross-reactivity, belong to a glycoprotein fraction and not to the galactan itself.

A new group of mitogenic lectins from invertebrate sources.

In the haemolymph of the Tridacnid bivalve clams anti-galactans occur which do not have only glycosubstance precipitating and cell agglutinating properties, but also show mitogenic activity with respect to the blast transformation of human peripheral lymphocytes. This new property can be inhibited in a specific way by galactans and is destroyed by the degradation of the mitogenic lectin into subunits by polymer bound pronase. Quite a number of invertebrate haemolymph samples and snail albumin gland extracts, containing agglutinin activity, proved to have no mitogenic potency. The only exception was found in an extract of the snail albumin gland of Ampullaria canaliculata which contained a strong mitogen of the lectin type.

Additional precipitation reactions of lectins with human serum glycoproteins.

Highly purified human serum glycoproteins were treated with neuraminidase and examined for their cross reaction with several lectins with anti-galactosyl specificity: beta-D-galactosyl structures are thought to be the main terminal sugar residues that become attached de novo after removal of neuraminic acid. The following lectins were tested: Tridacnin from the bivalve clams Tridacna maxima and Tridacna gigas, the agglutinin from the sponge Axinella polypoides, the lectin from the roach Rutilus rutilus and the plant lectins from Ricinus communis, Ononis spinosa, Glycine soja and Abrus precatorius. In agar gel diffusion, these purified and precipitating lectins gave more or less strong or negative results against the different neuraminidase-treated serum glycoproteins, thus indicating subtle differences with respect to their anti-galactosyl combining specificity. On the other hand, serum glycoproteins which reacted with the same lectin, did not always show complete identity lines. Finally, as revealed by these lectins, the carbohydrate moiety of serum glycoproteins may reflect a complex and broad spectrum of heterogeneity. This could lead to a more detailed understanding of the topographical and steric arrangement of the chemical structure and of the biological role of carbohydrate groups in these glycosubstances.