Glycosidases in porcine follicular fluid and their effect on zona pellucida-AWN 1 spermadhesin interaction

Oligosaccharide moieties on the surface of the oocyte belong to the key molecules that direct the course of fertilization and are subjected to changes during oocyte maturation in the follicle. In our study, we focused on the activities of five glycosidases in the fluids from porcine secondary and preovulatory follicles (α-l-fucosidase, α-d-galactosidase, β-d-galactosidase, β-D-N-acetylhexosaminidase, and α-d-mannosidase). All of them were detected active at neutral and acidic pH. However, changes in their activities associated with follicle development were observed only in the case of α-d-mannosidase, which was increased (P < 0.001), and β-d-galactosidase, which was decreased (P < 0.001) at neutral pH, and of α-d-galactosidase and β-N-acetylhexosaminidase, which were decreased (P < 0.0001) at the acidic pH. The comparison of glycosidases from follicular fluid and from blood plasma using red native electrophoresis revealed that most of the glycosidases are present in more than one isoenzyme form; some of them were detected mainly in the follicular fluid. Finally, we tested the effect of glycosidases on the interaction between zona pellucida and AWN 1 spermadhesin (putative sperm receptor of zona pellucida) and demonstrated that the effect of both β-d-galactosidase and to a lesser degree α-d-mannosidase led to a decrease in this interaction. We can hypothesize that these two glycosidases modulate the amount of zona pellucida oligosaccharide moieties and/or their structures for an optimal sperm binding in pigs.

Life cycle assessment comparison of photocatalytic coating and air purifier

This article presents a comparison of 2 very different options for removal of undesirable microorganisms and airborne pollutants from the indoor environment of hospitals, schools, homes, and other enclosed spaces using air purifiers and photocatalytic coatings based on nano titanium dioxide (TiO2 ). Both products were assessed by life cycle assessment (LCA) methodology from cradle-to-grave. The assessment also includes comparison of 2 different nano TiO2 production technologies, one by continuous hydrothermal synthesis and the other by a sulfate process. Results of the study showed a relatively large contribution of photocatalytic coatings to reducing the effects of selected indices in comparison with an air purifier, regardless of which nano TiO2 production method is used. Although the impacts of the sulfate process are significantly lower compared to those of hydrothermal synthesis when viewed in terms of production alone, taken in the context of the entire product life cycle, the net difference becomes less significant. The study has been elaborated within the Sustainable Hydrothermal Manufacturing of Nanomaterials (SHYMAN) project, which aims to develop competitive and sustainable continuous nanoparticle (NP) production technology based on supercritical hydrothermal synthesis. Integr Environ Assess Manag 2016;12:478-485. © 2016 SETAC.

Chicken and rabbit antibodies against porcine pepsinogen A

Isolated porcine pepsinogen A was used for the preparation of polyclonal rabbit and polyclonal chicken anti-pepsinogen A antibodies. Immunochemical properties of both immunoglobulin fractions were compared. The rabbit anti-serum was further purified using immobilized porcine pepsinogen A on magnetic cellulose beads and the resulting anti-pepsinogen A fraction proved to be applicable for the separation and the determination of porcine pepsinogen A. In contrary, antibodies prepared from chicken eggs by the same way have been found not suitable for the evaluation of the pepsinogen A level. Unexpectedly, the pre-immune fraction of chicken antibodies showed reactivity against porcine pepsinogen A and the affinity separation of specific polyclonal chicken anti-pepsinogen A antibodies on immobilized porcine pepsinogen A did not result in an enrichment of anti-pepsinogen A antibodies.

[Clinical variability of Best's disease]

Retrospective view of the various phenotypes 20 persons affected by classic solitary form of vitelliform macular dystrophy, in 3 pedigrees with autosomal dominant transmission and in 4 single cases. Long-term monitoring allows to observe the variability of expression, from classic course to peculiarity of the clinical expression in the disc development and their corresponding functions of the central retina.

Size exclusion chromatography as a tool for evaluation of fragmentation pattern of gastric mucins under non-degrading conditions

Gastric mucins are high molecular weight extracellular glycoproteins that play a major role in the protection of the gastrointestinal tract and besides that they are also involved in many disease processes. In the present study, size exclusion chromatography under non-degrading conditions was used to study the fragmentation pattern of native gastric mucins. The samples of gastric mucins of different origin obtained by an extraction of gastric mucosa with Tris-HCl buffer, pH 7.3 were separated using size exclusion chromatography on Sephadex G-100. While samples of rat gastric mucins are characterized by the presence of only high-molecular weight fraction of glycoproteins, fragmented mucin components in non-denaturated samples were observed in canine and human gastric mucins. Differences in the fragmentation pattern were observed in patients with ulcer diseases and gastric cancer. Degradation products of mucins were also detected using polyacrylamide gel electrophoresis in the presence of SDS.

Interaction of pepsin with aromatic amino acids and their derivatives immobilized to Sepharose

The interaction of porcine pepsin A with immobilized derivatives of aromatic amino acids was investigated. Divinyl sulfone-activated Sepharose was used to immobilize N-acetyl-l-phenylalanine and 3,5-diiodo-l-tyrosine via their free carboxyl groups and l-tyrosine via its amino group. Immobilized l-tyrosine was iodinated after coupling. The optimum conditions for the separation of porcine pepsin A using the prepared affinity carriers were studied and the following parameters were established: enzyme recovery, reproducibility of analyses, capacity and dependence of the elution peak area on the concentration of the loaded enzyme. The ability of the prepared affinity carriers to retain various types of proteins was compared under optimum conditions for porcine pepsin A separation. While immobilized 3,5-diiodo-l-tyrosine and iodinated l-tyrosine-Sepharose adsorbed relatively high amounts of bovine serum albumin and ovalbumin, only negligible amounts of these proteins were adsorbed to immobilized N-acetyl-l-phenylalanine. The behavior of porcine pepsin A was the same as its complex with pepstatin A on the prepared affinity carriers, indicating that the enzyme active site is not involved in the studied interaction.

Preliminary characterization of multiple hyaluronidase forms in boar reproductive tract

Hyaluronidases play an important role in gamete interaction and fertility in mammals. The objectives of the present study were to investigate multiple forms of the enzyme in boar reproductive tract using electrophoretic methods. Two forms of hyaluronidase (EC 3.2.1.35) were detected in boar seminal plasma (relative molecular masses of 55,000 and 65,000) using hyaluronic acid-substrate polyacrylamide gel electrophoresis in the presence of SDS. These two forms can be separated by means of affinity chromatography on Heparin-Sepharose. They differ, besides their affinity to heparin, also in the pH optimum of their enzymatic activity. The form with relative molecular mass of 55,000 was active both at the acidic (pH 3.7) and the neutral pH (pH 7.4) and was bound to immobilized heparin. The second form (relative molecular mass 65,000) was active only at acidic pH and did not interact with heparin. The same acidic-active form (65,000) was found in seminal vesicle fluids. The hyaluronidase form which is active both at the acidic and the neutral pH (51,000) was detected in epididymal fluid. In the detergent extracts of boar sperm, three active forms of the enzyme were found (relative molecular masses 55,000, 70,000 and 80,000). The form of relative molecular mass 55,000 was active in a wide range of pH (pH 3-8). The forms of relative molecular masses 70,000 and 80,000 were active only at neutral pH.

Origin, localization and binding abilities of boar DQH sperm surface protein tested by specific monoclonal antibodies

Seminal plasma proteins bind the sperm surface at ejaculation and may modulate several aspects of sperm activity during reproduction. DQH sperm surface protein, present in boar seminal plasma, shows affinity to phoshorylcholine, acidic polysaccharides, oviductal epithelium and zona pellucida glycoproteins. Monoclonal antibodies (MAbs) against DQH protein were prepared and used for determination of the DQH protein origin in boar reproductive organs, its localization on boar spermatozoa, and for investigation of its binding abilities in the porcine oviduct and to the zona pellucida of the oocyte. The mRNA transcript of DQH protein was found in seminal vesicles and not in the testis, epididymis and prostate. Its translated products were immunodetected by MAbs in seminal vesicle extract and fluid, in seminal vesicle tissue sections and on the membrane-associated acrosomal part of ejaculated spermatozoa. These results confirm the ability of DQH protein to bind the sperm surface at ejaculation and to participate in formation of the sperm reservoir in the porcine oviduct. Moreover, monoclonal antibodies reduced binding of sperm to oocytes and proved the role of DQH protein in the sperm-zona pellucida primary binding.

Separation, characterization and identification of boar seminal plasma proteins

Methods used for the isolation, separation and characterization of boar seminal plasma proteins are discussed, as well as techniques applied to study their binding properties. Attention is paid to interactions of these proteins with different types of saccharides and glycoconjugates, with membrane phospholipids, and to interactions between proteins. Boar seminal plasma contains different types of proteins: spermadhesins of the AQN and AWN families; DQH and PSP proteins belong to the most abundant. Some of these proteins are bound to the sperm surface during ejaculation and thus protein-coating layers of sperm are formed. Sperms coated with proteins participate in different types of interactions occurring in the course of the reproduction process, e.g. formation of the oviductal sperm reservoir, sperm capacitation, oocyte recognition and sperm binding to the oocyte.

Magnetic IDA-modified hydrophilic methacrylate-based polymer microspheres for IMAC protein separation

Preparation of a new type of magnetic non-porous poly(2-hydroxyethyl methacrylate-co-glycidyl methacrylate) microspheres with hydrophilic properties containing coupled iminodiacetic acid (IDA) is described. The prepared microspheres were used for the immobilization of Ni(II) or Fe(III) ions to show their application in protein binding studies. Human IgG was bound to magnetic Ni(II)-IDA-modified microspheres and conditions of its adsorption and elution were optimized. Non-specific binding of the protein to magnetic microspheres in the absence of Ni(II) ions was low. Fe(III) ions immobilized on magnetic IDA-modified microspheres were used for the specific binding of porcine pepsin, as a model phosphoprotein. The ability of phosphate buffer to release the adsorbed enzyme from the microspheres and a low adsorption of the dephosphorylated protein indicate the participation of phosphate groups in the pepsin interaction. The elaborated method represents a rapid technique that can be used not only for the separation of proteins but also for analytical purposes.

Saccharide-mediated interactions of boar sperm surface proteins with components of the porcine oviduct

The role of boar seminal plasma proteins attached to the sperm plasma membrane during ejaculation has been studied in saccharide-mediated events in the female reproductive tract. Heparin-binding (Hep(+)) proteins (DQH sperm surface protein, and AQN and AWN spermadhesins) and their aggregated forms (fractions II and III) interacted more strongly with both oviductal epithelium cells and fluid than non-heparin-binding (Hep(-)) proteins (PSP I and PSP II spermadhesins) and their heterodimer (fraction IV), and interactions correlate with affinity of these proteins to yeast mannan. Indirect immunofluorescence (IMF) showed that the AQN 1 spermadhesin and fraction II bind to the apical glycocalyx of the ampulla, as well as the isthmic and uterine tubal junction regions of the oviductal sections. IMF demonstrated the recognition of AQN 1 and fraction II and mannosyl components of oviductal epithelium. We suggest that Hep(+) proteins (especially AQN 1, fraction II) on sperm could enable sperm binding to oviductal epithelium and thus participate in formation of the sperm oviductal reservoir. Interactions of Hep(+) proteins to oviductal epithelium were inhibited by mannan, hyaluronic acid and sialylated O-glycoproteins. No or slight inhibition was observed with sulphated polysaccharides (heparin, chondroitin sulphate) and simple monosaccharides. Besides that, attachment of boar seminal plasma proteins to oviductal epithelium cells was affected by oviductal fluid, the natural environment in the oviduct. Moreover, the ability of hyaluronic acid to inhibit the interaction of sperm surface proteins to the oviduct might play a role in sperm release from the oviductal reservoir and in the capacitation process.

Affinity liquid chromatography and capillary electrophoresis of seminal plasma proteins

Interactions of boar, bull, and human seminal plasma proteins with heparin and phosphorylcholine were studied by affinity LC using heparin immobilized to a Toyopearl support. A step gradient elution from 0.15 to 1.50 M NaCl was employed to elute the seminal plasma proteins. Relative amounts of the heparin-binding fraction of seminal plasma proteins (H+) in seminal plasma of three species were determined. Further on, the fraction of seminal plasma proteins interacting with phosphorylcholine-binding proteins (P+) was evaluated. P+ proteins were not found in human seminal plasma and their highest amount was present in bull seminal plasma. A CE method was developed for separation of seminal plasma proteins. Various capillaries and separation conditions were tested; the best resolution was obtained in a bare-silica capillary, with a micellar system consisting of a 0.02 M borate buffer and 0.05 M SDS pH 10.0. The optimized conditions were applied to the identification of the components in boar plasma.

Preparation and testing of stationary phases and modified capillaries for affinity chromatography and affinity capillary electrophoresis of pepsin

Three stationary phases have been prepared for affinity liquid chromatography isolation and separation of porcine and human pepsin. The phases contain 3,5-diiodo-L-tyrosine (DIT) bound to the supports HEMA BIO VS, HEMA BIO E and EPOXY TOYOPEARL. These phases have been tested on a model sample of porcine pepsin A and applied to human pepsin. Fractions have been collected and the chymase activity determined in selected analyses. For affinity CE, capillaries have been prepared by modifying the wall with 3-aminopropyltriethoxysilane, followed either by direct binding of DIT, or by binding L-tyrosine that was subsequently iodated. The dissociation constant K(d) has been determined for the pepsin-DIT complex from the changes in the electrophoretic mobilities.

Characterization of human seminal plasma proteins homologous to boar AQN spermadhesins

Spermadhesins, proteins secreted by the boar sexual accessory glands, are believed to play an important role in sperm capacitation and primary contact of sperm and egg. We have previously found human seminal plasma proteins immunobiochemically related to boar AQN and AWN spermadhesins. In this study, we characterized further the AQN spermadhesin-related proteins, here designated as hSA (human spermadhesin-like) proteins. On Western blot, we immunodetected 14, 16 and 18 kDa forms of hSA proteins (hSA-14, hSA-16 and hSA-18, respectively) cross-reacting with rabbit antibody against AQN spermadhesins. Each relative molecular-mass form of hSA comprised three isoelectric isoforms (6.0, 6.8 and 8.4) as shown by 2D-PAGE. Glycoprotein analysis revealed that all hSA-16 and hSA-18 isoforms were N-glycosylated, and those of hSA-14 were non-glycosylated. Two isoforms of hSA-14 (pI 6.0 and 8.4) had affinity to heparin. Size-exclusion chromatography of human seminal plasma indicated that hSA proteins formed high molecular-mass complexes either with other hSA proteins or with seminal plasma lactoferrin and/or its fragments. Similarity of biochemical properties (relative molecular masses, isoelectric points and existence of non- and N-glycosylated forms) of hSA proteins and those of boar AQN spermadhesins, together with a previously described N-terminal amino acid sequence of one hSA protein identical to AQN spermadhesins, imply that hSA proteins are structurally related to boar AQN spermadhesins. However, localization of hSA proteins on the sperm tail and neck suggests that their biological role differs from that of boar AQN spermadhesins located on the sperm head.

Mannan-binding proteins from boar seminal plasma

The interaction of boar seminal plasma proteins and sperm with yeast mannan was investigated by the enzyme-linked binding assay (ELBA) and specific detection of proteins after SDS electrophoresis and blotting using biotinylated derivative of the polysaccharide. Heparin-binding proteins (especially AQN 1 and DQH proteins) and their aggregated forms showed affinity to yeast mannan. Besides that, these proteins were shown to bind to oviductal epithelium. The mannan-binding activity of boar proteins and sperm was inhibited most efficiently by ovomucoid, ovalbumin and N-glycans released from ovalbumin, but not with d-glucose, d-mannose and their phosphates. On the other hand, yeast mannan inhibited both the interaction of boar seminal plasma and sperm with heparin and the binding of these proteins to porcine oviductal epithelium. Yeast mannan immobilized to divinyl sulfone-activated Sepharose was used for the isolation of mannan-binding proteins. Proteins adsorbed to the immobilized polysaccharide were analyzed by RP-HPLC, SDS electrophoresis and N-terminal amino acid sequencing. AQN and AWN spermadhesins and DQH protein (names are derived from the N-terminal amino acid sequence) were identified as components of the isolated fraction. The results suggest an involvement of mannan-binding proteins in the formation of the sperm oviductal reservoir in pig. The ability of these proteins to interact both the complex d-mannose-containing saccharide structures and the heparin may also play an important role in sperm release from the oviductal reservoir or the capacitation process.

Affinity chromatography of porcine pepsin and pepsinogen using immobilized ligands derived from the specific substrate for this enzyme

Affinity chromatography of porcine protease and its zymogen was carried out on immobilized components of specific substrate used for the pepsin determination. For the immobilization of N-acetyl-L-phenylalanine and iodinated derivative of L-tyrosine, divinyl sulfone activated Sepharose was used. Ligands with blocked amino group and free carboxyl one were linked to Sepharose via ethylene diamine spacer using carbodiimide reaction. Conditions of affinity chromatography of porcine pepsin and pepsinogen on the prepared carriers were optimized: the effect of pH, ionic strength and a nature of the buffers used on adsorption of the enzyme and zymogen to an affinity carrier, as well as their elution was studied. The following parameters were taken into consideration: capacity of the prepared affinity matrices, reproducibility of experiments and the enzyme stability. Pepsin was adsorbed to both immobilized ligands at pH 3.5-4.0; for the elution of the enzyme it was necessary to increase ionic strength (up to 0.5 M). For the adsorption of pepsinogen pH 5.2 was found to be optimum, for its desorption, an increase of ionic strength was used.

Aggregated Forms of Bull Seminal Plasma Proteins and Their Heparin-Binding Activity

Heparin-binding activity of bull seminal plasma proteins was shown to be dependent on their aggregation state. The protein fraction interacting with immobilized heparin was characterized by large polydispersity in the region of molecular weight of 60 000-10 000, while that not retained on the affinity carrier was present as aggregates with molecular weight >100 000. Components of heparin-binding and non-heparin-binding fractions were separated by RP HPLC (reversed-phase HPLC) and analyzed by SDS (sodium dodecyl sulfate) electrophoresis and N-terminal sequencing. Size exclusion chromatography of whole seminal plasma and heparin-binding proteins in the presence of D-fructose (as a component of seminal plasma) showed that the region of molecular weights of protein-associated forms was shifted to lower values. An increase of heparin-binding activity of bull proteins, as determined by ELBA (Enzyme-Linked Binding Assay), correlates with a decrease of their aggregation state. The modulation of the aggregation state of bull proteins by seminal plasma components and, in this way, also of their heparin-binding properties suggests possible mechanisms for capacitation mediated by these proteins.

Boar Seminal Plasma Proteins and Their Binding Properties. A Review

Binding properties of a group of proteins isolated from boar seminal plasma and their role in the fertilization process are discussed. Boar seminal plasma contains different types of proteins: spermadhesins of AQN and AWN family, DQH and PSP proteins belong to the most abundant. Some of these proteins are bound to the sperm surface during ejaculation and thus protein-coating layers are formed. Sperms coated with proteins participate in different types of interactions in the following steps of the fertilization process: formation of oviductal sperm reservoir, sperm capacitation, oocyte recognition and sperm binding. Saccharide-based interactions of boar seminal plasma proteins play role in the binding of sperm to oviductal epithelium, in sperm capacitation and primary binding of sperm to zona pellucida. An interaction with phospholipid components is responsible for the protein adsorption to sperm membrane. Interactions between proteins participate in the arrangement and remodelling of sperm-coating layers. Study of boar seminal plasma proteins, their characterization and elucidation of their interactions will contribute to understanding the fertilization process. A review with 82 references.

Mutual Interactions of Boar Seminal Plasma Proteins Studied by Immunological and Chromatographic Methods

PROBLEM

Boar seminal plasma contains various types of proteins. Most of them belong to spermadhesins and some of them contain fibronectin type II domain. Almost all of these proteins are present under physiological conditions in aggregated forms differing in their relative molecular mass, composition, and binding properties. The study of mutual specific interactions between proteins of boar seminal plasma that could be involved in the formation of aggregated forms and most probably of sperm coating layers is the subject of our present communication.

METHODS OF STUDY

Aggregated forms of boar seminal plasma proteins separated by size exclusion chromatography were analysed by Reversed-phase High-performance Liquid Chromatography (RP HPLC), SDS-PAGE and immunochemical methods (ELISA and immunoblotting). Mutual interactions between proteins were investigated by size exclusion chromatography of a mixture of separated monomer proteins and affinity chromatography of boar seminal plasma on immobilized spermadhesins.

RESULTS

Composition of proteins that are adsorbed from boar seminal plasma to immobilized spermadhesins corresponds to that of aggregated forms found in seminal plasma. Mutual interactions between monomer forms observed by size exclusion chromatography are in good agreement with results of affinity chromatography. An existence of interactions between spermadhesins of the AQN and AWN families and the DQH sperm surface protein, as well as between proteins involved in the formation of heterodimer porcine seminal plasma I (PSP I)/PSP II was proved.

CONCLUSION

Mutual specific interactions between protein components of boar seminal plasma were shown. These interactions participate in the formation of aggregated forms of proteins in seminal plasma and probably also in the arrangement and remodelling of protein coating layers of sperm. Aggregation of seminal plasma proteins is probably an important phenomenon in the fertilization process.

Proteinase inhibitors in aggregated forms of boar seminal plasma proteins

Boar seminal plasma proteins were separated by gel chromatography on Sephadex G-75 into five fractions (I-V). Serine proteinase inhibitors were found mainly in the protein fraction with relative molecular weight 5-25kDa. Small amounts of these inhibitors were also found in the high molecular weight protein fraction (M(r)>100kDa). The protein fraction containing most of the proteinase inhibitory activity was further separated by RP HPLC. Isolated proteins were characterized by SDS electrophoresis and immunoblotting, N-terminal amino acid sequencing and by determination of the proteinase inhibitory activity. In the fraction containing proteinase inhibitors, also beta-microseminoprotein (beta-MSP), AQN 1 and lactoferrin were identified. The possible existence of complexes of protein components in the fraction with relative molecular weight 5-25kDa was studied in detail using gel chromatographic separation on Sephadex G-50. A part of proteinase inhibitors with M(r) 8kDa was eluted together with AQN 1 spermadhesin. An interaction of isolated spermadhesin AQN 1 and proteinase inhibitor was shown.

Some potentialities and drawbacks of contemporary size-exclusion chromatography

The present state of the chromatographic techniques based on differentiation of solutes according to their molecular sizes is briefly surveyed. Attention is centred on high-performance techniques applied to purification and characterization of natural macromolecules, and on discussion of the chromatographic approaches to the determination of the molecular masses and molecular mass distributions of both natural and synthetic polymers. The basic requirements on the selection of the separation system and the experimental conditions are summarized, demonstrated on a few examples and critically evaluated.

Affinity chromatography of bull seminal proteins on mannan-Sepharose

The interaction of bull seminal plasma proteins and sperm with mannan was investigated using an enzyme-linked binding assay (ELBA). A high mannan-binding activity was found in the protein fraction interacting with heparin. Mannan binding to seminal plasma proteins was inhibited by D-mannose and D-fructose, but not by D-mannose-6-phosphate, D-glucose-6-phosphate, ovalbumin and ovomucoid. Mannan inhibited the binding of bovine zona pellucida glycoproteins both to bull sperm and seminal plasma proteins. Yeast mannan immobilized to divinyl sulfone-activated Sepharose was used for the isolation of mannan-binding proteins. The protein components of this fraction were identified on the basis of relative molecular mass determination and N-terminal amino acid sequencing: RNAase dimer, PDC-109 and a protein homologous to BSP-30K (relative molecular mass 14,500). The isolated proteins were characterized by a high zona pellucida binding activity.

Characterization of proteins from boar prostate

PROBLEM

Most components of seminal plasma are secreted by accessory sexual glands: seminal vesicle, prostate gland and bulbourethral gland. The portion of proteins secreted by prostate gland differs in various species. Characterization of boar prostate proteins is the subject of this communication.

METHODS OF STUDY

Proteins of boar prostate gland were separated by affinity chromatography on heparin-polyacrylamide to non-heparin-binding (H-) and heparin-binding (H+) fractions. The H- and H+ fractions were subjected to reverse phase high performance liquid chromatography (RP HPLC) and their elution profiles were compared with those of the H- and H+ fractions of boar seminal plasma. The isolated proteins were characterized by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), immunodetection, N-terminal amino acid sequencing and mass spectrometry (MALDI).

RESULTS

The following proteins of boar prostate secretion were identified: beta-microseminoprotein, serotransferrin, serum albumin, myoglobin and PSP I and PSP II spermadhesins.

CONCLUSION

Presented results demonstrate composition of the main proteins of boar prostate secretion. Beta-Microseminoprotein was found to be a major protein of prostate secretion. PSP I and PSP II, major proteins of the H- fraction of boar seminal plasma, were found in boar prostate secretion in lower amounts. The major proteins of the H+ fraction of boar seminal plasma (AQN, AWN) were not detected in prostate secretion.

Proteomics of allergens

The present state of proteomics research is generally outlined and the character of allergenic compounds briefly elucidated. The principles of experimental approaches to isolation, purification, identification and characterization of allergens and to monitoring of their biological activity are described, with emphasis on the most modern methods. Selected examples are given for illustration and important results are summarized in tables.

Aromatic amino acids and their derivatives as ligands for the isolation of aspartic proteinases

Affinity chromatography was used to study an interaction of aspartic proteinases with immobilized aromatic amino acids and their derivatives. The following ligands were used: L-tyrosine, 3-iodo-L-tyrosine, 3,5-diiodo-L-tyrosine, L-phenylalanine, p-iodo-L-phenylalanine and N-acetyl-L-phenylalanine. With the exception of the last one, ligands were coupled directly to divinyl sulfone activated Sepharose 4B. For the preparation of immobilized N-acetyl-L-phenylalanine, divinyl sulfone activated Sepharose 4-B with linked ethylene diamine was used. Porcine pepsin was used for the evaluation of the capacity of the prepared affinity carriers. The capacity of the immobilized amino acid derivatives significantly increased in comparison with the non-derivatized amino acids. The prepared immobilized ligands were further used for the separation of human pepsinogens.

Immobilization of L-glyceryl phosphorylcholine: isolation of phosphorylcholine-binding proteins from seminal plasma

The preparation of an affinity sorbent containing immobilized L-glyceryl phosphorylcholine for affinity chromatography of phosphorylcholine-binding proteins from seminal plasma is described. The ligand was coupled either after its maleinylation to poly(acrylamide-allyl amine) copolymer or directly to divinyl sulfone-activated Sepharose. The prepared phosphorylcholine derivative coupled to Sepharose was used for affinity chromatography of phosphorylcholine-binding proteins from bull and boar seminal plasma. Adsorbed proteins were specifically eluted with phosphorylcholine solution. Isolated phosphorylcholine-binding proteins were characterized by SDS electrophoresis and HPLC with reversed phase. Composition of the boar phosphorylcholine-binding fraction obtained by affinity chromatography on immobilized L-glyceryl phosphorylcholine was compared with that eluted from immobilized heparin by the phosphorylcholine solution. No phosphorylcholine-binding proteins were found in human seminal plasma.

Isolation of non-heparin-binding and heparin-binding proteins of boar prostate

Proteins of boar prostate secretion were separated by affinity chromatography on heparin-polyacrylamide to non-heparin-binding (H) and heparin-binding (H+) protein fractions. H- and H+ fractions were then subjected to RP HPLC. Elution profiles of H-and H+ fractions of prostate secretion were compared with those of seminal plasma and the amounts of corresponding proteins were compared. Besides, the isolated proteins were characterized by SDS-PAGE. In the H- fraction of prostate secretion, PSP I and PSP II spermadhesins and in the H+ fraction AQN 2 and AWN 1 spermadhesins were found in substantially lower amounts than in seminal plasma. On the contrary, beta-microseminoprotein was identified in abundant amounts both in H- and H+ fractions of boar prostate secretion. AQN 2 and AWN 1 spermadhesins were proved by their antibodies. Some seminal plasma proteins originating mainly in seminal vesicles could also be secreted by the prostatic gland. beta-Microseminoprotein was found to be produced mainly by the prostate.

D-fructose-binding proteins in bull seminal plasma: isolation and characterization

The heparin-binding activity of bull seminal plasma proteins was inhibited by D-fructose, D-glucose, inulin and glycogen; D-galactose, dextran and mannan had no effect. While the ejaculated sperm-heparin interaction was not influenced by the presence of saccharides, the heparin-binding activity of epididymal sperm was inhibited by D-fructose. The results of the binding studies were confirmed by affinity chromatography on immobilized heparin followed by elution with monosaccharides. Proteins adsorbed to a heparin-polyacrylamide column and eluted with D-fructose were analyzed by RP HPLC, SDS electrophoresis and by determination of the N-terminal amino-acid sequence. RNAase dimer, PDC-109 and metalloproteinase inhibitor (TIMP-2) were identified.

Heparin-binding proteins of human seminal plasma homologous with boar spermadhesins

Protein homologues to boar seminal plasma spermadhesins with the N-terminal sequence AQN (AQN spermadhesins) and with the N-terminal sequence AWN (AWN spermadhesins) were detected in human seminal plasma and characterized. They were isolated as heparin-binding (HB) proteins from human seminal plasma by affinity chromatography on heparin-Sepharose and then separated into 12 fractions (HB1-HB12) by RP HPLC or into four major fractions (HB-I-HB-IV) by gel filtration. Rabbit antibody against boar seminal plasma AQN 1 spermadhesin cross-reacted with 10-14 kDa proteins of fraction HB7, and antibody against AWN 1 spermadhesin cross-reacted with 11-14 kDa proteins of fractions HB9 and HB11. Both antibodies interacted with 10-14 kDa proteins in fractions HB-I and HB-II. The N-terminal amino acid sequence (1)AQNKG(5)... was determined in the 14 kDa protein of fraction HB-I cross-reacting with AQN 1 antibodies. A component detected among 10-14 kDa proteins of HB7 cross-reacting with rabbit antiserum against AQN 1 had the N-terminal sequence (1)GELKFVTLVFAVGDYE(16), which is similar to the sequence of a fragment of prostatic acid phosphatase. Lactoferrin and its fragments were immunodetected with rabbit antibody against human milk lactoferrin in fractions HB7-HB11. This was proved by N-terminal sequencing of a lactoferrin fragment immunodetected in fraction HB7. N-terminal amino acid sequence analysis of the dominant component of fraction HB2 revealed the presence of a fragment of semenogelin I.

Affinity chromatography of porcine pepsin on different types of immobilized 3,5-diiodo-L-tyrosine

The preparation of affinity sorbents containing immobilized iodinated derivatives of L-tyrosine for the affinity chromatography of porcine pepsin is described. The ligand was coupled either to Sepharose 4B or bead cellulose after the divinylsulfone activation or to Sepharose 4B after the activation with 2,4,6-trichloro-1,3,5-triazine. The highest capacity for porcine pepsin was found in the case of 3,5-diiodo-L-tyrosine coupled to divinylsulfone-activated Sepharose.

Aggregated and monomeric forms of proteins in boar seminal plasma: characterization and binding properties

Boar seminal plasma was separated into five protein fractions (I-V) (>100, 55, 45, 30, 5-15 kDa) by gel filtration chromatography on Sephadex G-75 SF at pH 7.4. RP HPLC of protein fractions I-V and N-terminal sequencing of their individual components revealed that high-molecular-weight aggregates consisted mainly of DQH sperm surface protein and AQN, AWN, PSP II spermadhesins, while fraction IV consisted of heterodimers of PSP spermadhesins only. Spermadhesins as monomers were present in seminal plasma in a very low amount. Biotinylated fractions I-IV containing AWN, AQN, DQH, and PSP proteins were bound to boar epididymal and ejaculated spermatozoa with the same efficiency. Aggregates containing AWN, AQN, DQH, PSP II proteins (fractions I-III) and their HPLC-separated monomeric forms interacted with phosphorylcholine. Aggregates containing the DQH protein and AWN spermadhesins as well as their separated monomeric proteins interacted strongly with acidic polysaccharides. PSP II interacted with some acidic polysaccharides, while the fraction IV corresponding to heterodimer PSP IPSP II did not show any binding to acidic polysaccharides and zona pellucida. Fractions I-III showed affinity to cholesterol. The strongest interaction was observed between biotinylated glycoproteins of porcine zona pellucida and AWN 1-containing aggregates and separated proteins. AQN 1 spermadhesin effectively blocked the sperm binding to oocytes. These results suggest that under physiological conditions, the aggregated forms of seminal plasma proteins (DQH, AQN, AWN, PSP II) rather than the individual proteins might take part in coating the sperm surface, in sperm capacitation and in primary binding of spermatozoa to zona pellucida of the ovum.

Effects of electrolyte modification and capillary coating on separation of glycoprotein isoforms by capillary electrophoresis

The capillary electrophoresis (CE) running electrolyte composition was optimized for the separation of selected glycoproteins. A good separation of the ovalbumin (OV) and alpha-acid glycoprotein (AAG) isoforms was achieved in 20 mmol x L(-1) N-(2-hydroxyethyl)piperazine-2'-(2-ethanesulfonic acid) (HEPES) at pH 7.0, in 20 mmol x L(-1) phosphate, pH 7.0, or in 25 mmol x L(-1) borate, pH 7.9. Various ways of suppression of the glycoprotein adsorption onto the capillary wall were compared. Alpha, omega-diamine alkanes and bis(aminoalkyl) amines were added to the CE buffers, the optimized concentration being 1 mmol x L(-1) in 20 mmol x L(-1) phosphate buffer. The OV and AAG isoforms could be separated using all the alpha,omega-diamine alkanes or bis(2-aminoethyl)amine. The length of the alkyl chain in the diaminoalkane did not influence the separation. The separation of the isoforms of pollen allergens was also tested. The effects of modification of the capillary wall by succinyl-poly-L-lysine and hydrophilic CElect-P1 capillary were compared. A decrease in the glycoprotein and protein adsorption resulted in an improved separation of the isoforms.

Sperm surface proteins in mammalian fertilization

Boar seminal plasma was separated into five protein fractions (I-V) (> 100, 55, 45, 30, 5-15 kDa) by gel chromatography on Sephadex G-75 SF at pH 7.2. RP-HPLC of protein fractions I-V and N-terminal sequencing of their individual components revealed that the high-molecular-weight aggregates consisted mainly of DQH sperm surface protein and AQN, AWN, PSP II spermadhesins, whereas fraction IV consisted of heterodimers of PSP spermadhesins only. Spermadhesins as monomers were present in seminal plasma in a very low amount. Aggregates containing the DQH protein and AWN spermadhesins as well as HPLC-separated monomeric proteins interacted strongly with acidic polysaccharides. The strongest interaction was observed between biotinylated glycoproteins of porcine zona pellucida and AWN 1-containing aggregates and separated proteins. PSP II interacted with some acidic polysaccharides, whereas the fraction IV corresponding to heterodimer PSP I/PSP II did not show any binding to acidic polysaccharides and zona pellucida. Aggregates containing AWN, AQN, DQH, PSP II proteins, and their separated monomeric forms (fractions I-III) interacted with phosphorylcholine. Fractions I-III showed affinity to cholesterol. Biotinylated aggregates containing AWN, AQN, DQH, and PSP proteins (fractions I-IV) bound stronger to boar epididymal spermatozoa than to ejaculated spermatozoa. These results suggest that under physiological conditions, the aggregates of seminal plasma proteins (DQH, AQN, AWN, PSP II) rather than the individual proteins might take part in coating the sperm surface, in sperm capacitation, and in primary binding of spermatozoa to zona pellucida of the ovum.

Aggregated forms of heparin-binding and non-heparin-binding proteins of boar seminal plasma and their binding properties

Boar seminal plasma proteins were separated by affinity chromatography on immobilized heparin into two portions: heparin-binding (H+) and non-heparin-binding (H-) proteins. Gel chromatography of the H+ portion yielded four main protein fractions of >150, 45, 30 and 20 kDa, while that of the H- portion resulted in the separation into three main protein fractions of >150, 30 and 20 kDa. HPLC analysis and N-terminal sequencing used to characterize the composition of the protein fractions obtained by gel chromatography revealed that all consisted of low (12-16 kDa) molecular weight components: the H+ fraction consisted of DQH sperm protein, AQN and AWN spermadhesins whereas the H- fraction consisted of PSPI and PSPII spermadhesins. The high molecular weight values of fractions obtained by gel chromatography thus suggest that the proteins are present in boar seminal plasma in the form of aggregates. Interactions of individual boar seminal plasma proteins and their aggregates present in the H+ and H- fractions with acid polysaccharides were estimated.

Interaction of bull, stallion and boar seminal plasma proteins and sperms with acidic polysaccharides

The interaction of seminal plasma proteins, sperms and detergent-released sperm proteins of three species with different types of acidic polysaccharides was studied. Heparin-binding activity of boar, bull and stallion seminal plasma proteins, sperms and sperm proteins was compared with their ability to interact with polysaccharides differing in the presence of the sulfate groups or in their saccharide moiety (chondroitin sulfate, dextran sulfate, fucoidan, hyaluronic acid). Bull seminal plasma proteins were characterized by higher affinity to heparin, fucoidan and dextran sulfate, while significant differences between different types of polysaccharides were detected in the case of boar proteins. Sperm protein interactions with acidic polysaccharides in bull and stallion were analogous to the binding of seminal plasma proteins. Bull and stallion seminal plasma proteins inhibited the interaction of corresponding sperm proteins with acidic polysaccharides.

Saccharide-binding properties of boar AQN spermadhesins and DQH sperm surface protein

Heparin-binding proteins BHB 2-BHB 5 were purified from boar seminal plasma by affinity chromatography on a heparin-polyacrylamide column and reversed phase HPLC. Three of the proteins, BHB 3-BHB 5, were found to be identical to spermadhesins AQN 1-AQN 3 isolated from boar spermatozoa. The lectin-like properties of the isolated proteins BHB 2-BHB 5 were studied using double-diffusion in agarose gel, enzyme-linked binding assay, and inhibition assays of erythroagglutinating activity. It was found that proteins BHB 3-BHB 5 (spermadhesins AQN 1-AQN 3) interacted with glycoproteins containing O-glycosidically bound oligosaccharide chains, but not with those containing only N-linked carbohydrate chains. The strongest interaction was observed between BHB 3 (AQN 1) and desialyzed bovine submaxillary gland mucin, the glycoprotein containing only O-glycosidically linked saccharides. No interaction of BHB 3-BHB 5 proteins with simple saccharides, their derivatives or acidic polysaccharides was observed. Both the hemagglutinating activity and saccharide-binding properties of BHB 2 protein were quite different. Agglutinating activity of human erythrocytes by BHB 2 protein was significantly higher than that by BHB 3-BHB 5 proteins (AQN spermadhesins). In contrast to AQN spermadhesins, BHB 2 protein (DQH sperm surface protein) interacted strongly with acidic polysaccharides and sialyzed glycoproteins, but no binding of desialyzed glycoproteins as well as N-acetyl-alpha-D-galactosaminyl-O-serine,simple monosaccharides and amino sugars was observed.

Preparation of Biotinylated and FITC-Labelled Phosphorylcholine Poly(acrylamide) Derivatives and Their Application for Protein Ligand-Binding Studies

Biotin- and FITC-labelled water-soluble poly(acrylamide) derivatives of phosphorylcholine were prepared by coupling either maleinylated (a) or periodate-oxidized (b) L-glyceryl phosphorylcholine to poly-(acrylamide-allylamine) copolymer. Biotinylated phosphorylcholine poly(acrylamide) derivatives of both types were tested with Limulus polyphemus C-reactive protein and were used for the study of the phosphorylcholine-binding properties of boar seminal plasma proteins. Binding sites for phosphorylcholine on the surface of bull sperms were visualized using a FITC-labelled derivative of the ligand.

Determination of the complete covalent structure of the major glycoform of DQH sperm surface protein, a novel trypsin-resistant boar seminal plasma O-glycoprotein related to pB1 protein

The complete covalent structure of a novel boar DQH sperm surface protein resistant to many classical procedures of enzymatic fragmentation was determined. The relative molecular mass of the major form of this protein determined by ESI-MS and MALDI-MS was 13,065.2+/-1.0 and 13,065.1, respectively. However, additional peaks differing by 162 Da (i.e., minus hexose), 365 Da (i.e., minus hexose and N-acetylhexosamine), 146 Da (i.e., plus deoxyhexose), and 291 Da (i.e., plus sialic acid) indicated the heterogeneity due to differences in glycosylation. The complete covalent structure of the protein was determined using automated Edman degradation, MALDI-MS, and post-source decay (PSD) MALDI-MS, and shown to consist of N-terminal O-glycosylated peptide followed by two fibronectin type II repeats. The carbohydrates are O-glycosidically linked to threonine 10, as confirmed by PSD MALDI-MS of the isolated N-terminal glycopeptide. Eight cysteine residues of the protein form four disulfide bridges, the positions of which were assigned from MALDI-MS and Edman degradation data. We conclude that mass spectral techniques provide an indispensable tool for the detailed analysis of the covalent structure of proteins, especially those that are refractory to standard approaches of protein chemistry.

Peptide Maps of Porcine Pepsin Prepared Using Soluble and Immobilized α-Chymotrypsin

Reverse-phase high performance liquid chromatography (RP-HPLC) was used for characterization of peptide maps of porcine pepsin using soluble or immobilized α-chymotrypsin. The immobilized enzyme was prepared by its coupling to periodate-oxidized poly(acrylamide-co-allyl α-D-galactoside or allyl β-lactoside) copolymer (O-glycosylated acrylamide copolymer). After sodium cyanoborohydride reduction, a stable linkage was formed. Specific activity of α-chymotrypsin, linked to the copolymer containing bound α-D-galactosyl or β-lactosyl residues was 59.1 or 314.4% activity of soluble enzyme.

Spermadhesins of the AQN and AWN families, DQH sperm surface protein and HNK protein in the heparin-binding fraction of boar seminal plasma

Heparin-binding proteins (designated BHB-2-BHB-9) were isolated from boar seminal plasma by affinity chromatography on heparin immobilized on polyacrylamide gel, followed by reverse phase HPLC. According to their N-terminal amino acid sequences, BHB-3-BHB-5 belong to the AQN family of spermadhesins and BHB-7-BHB-9 to the AWN family. BHB-6 is composed of two different proteins. The dominant protein (14 kDa) has the N-terminal amino acid sequence HNKQEGRDHD that is identical to the sequence of human semenogelin at positions 85-94. The minor proteins (16 and 17 kDa) belong to the AWN family of spermadhesins. The 14 kDa HNK protein does not crossreact with antibodies against AQN or AWN spermadhesins. BHB-2 also binds to the acrosome of boar epididymal spermatozoa but has the N-terminal sequence DQH. Therefore, basic protein BHB-2 belongs to a new family of DQH sperm surface proteins that are homologous to the acidic proteins from bull and stallion seminal plasma, to the collagen binding domain II in fibronectin and to the leucocyte cell-cell adhesion regulator, but are not homologous to AQN or AWN spermadhesins. Nevertheless, anti-AQN-1 spermadhesin antibodies crossreact strongly with DQH protein. All boar heparin-binding proteins bind concanavalin A indicating their glycoprotein nature, which was proved by the detection of glucosamine and galactosamine residues in their molecules. Furthermore, spermadhesins interact with zona pellucida, protease inhibitors and a polyacrylamide derivative of heparin. Affinity chromatography experiments showed that the DQH protein bound to gelatin-agarose together with the AWN proteins and that the DQH protein and AQN-1 spermadhesin belong to the phosphoryl choline binding proteins.