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

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.

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.

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.

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.

Sample preparation for peptides and proteins in biological matrices prior to liquid chromatography and capillary zone electrophoresis

The determination of peptides and proteins in a biological matrix normally includes a sample-preparation step to obtain a sample that can be injected into a separation system in such a way that peptides and proteins of interest can be determined qualitatively and/or quantitatively. This can be a rather challenging, labourious and/or time-consuming process. The extract obtained after sample preparation is further separated using a compatible separation system. Liquid chromatography (LC) is the generally applied technique for this purpose, but capillary zone electrophoresis (CZE) is an alternative, providing fast, versatile and efficient separations. In this review, the recent developments in the combination of sample-preparation procedures with LC and CZE, for the determination of peptides and proteins, will be discussed. Emphasis will be on purification from and determination in complex biological matrices (plasma, cell lysates, etc.) of these compounds and little attention will be paid to the proteomics area. Additional focus will be put on sample-preparation conditions, which can be 'hard' or 'soft', and on selectivity issues. Selectivity issues will be addressed in combination with the used separation technique and a comparison between LC and CZE will be made.

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.