Fabian Rueda - Academia.edu (original) (raw)
Papers by Fabian Rueda
Tropical Life Sciences Research
The sperm interacts with seminal plasma proteins during its transport through the female reproduc... more The sperm interacts with seminal plasma proteins during its transport through the female reproductive tract to reach the oocyte. Seminal plasma proteins have been associated as biomarkers of fertility in bovine males, while two-dimensional electrophoresis in polyacrylamide gels under denaturing conditions (2D-PAGE) is a useful technique for their separation, allowing their subsequent analysis with the aid of specialized software. Brahman bulls are known for their tolerance to tropical conditions such as low-quality pastures, high temperatures, and relative humidity as well as moderate resistance to infestations by parasites and insects. The present study describes the two-dimensional electrophoretic profiles of the seminal plasma proteins in the rainy and dry seasons, associating them with the fertility of Brahman bulls in the Colombian Orinoquía in a 90-days breeding season and a single-sire mating system (1 bull per 50 Brahman cows) with 60 consecutive days of rest. The fertility-...
Revista de Investigaciones Veterinarias del Perú
El objetivo del estudio fue comparar los niveles de la hormona antimülleriana (AMH) en hembras Br... more El objetivo del estudio fue comparar los niveles de la hormona antimülleriana (AMH) en hembras Brahman y Blanco Orejinegro donadoras de ovocitos y su relación con la reserva ovárica y producción de embriones in vitro. Se obtuvieron ovocitos de 42 hembras Brahman y 38 Blanco Orejinegro mediante punción ovárica guiada por ultrasonido (OPU). Se colectaron muestras de sangre previo a la OPU para la determinación de las concentraciones séricas de AMH. Los ovocitos y embriones se cultivaron de manera individual para cada donante. Los resultaron mostraron que las concentraciones séricas de AMH fueron de 0.78 ± 0.34 ng/ml (0.09-1.89 ng/ml) para las vacas Brahman y de 0.72 ± 0.32 ng/ml (0.13-1.19 ng/ml) para las Blanco Orejinegro. La correlación entre la concentración de AMH y el número de folículos fue de r=0.77 y r=0.74 para las vacas Brahman y Blanco Orejinegro, respectivamente., así como una correlación positiva entre la concentración de AMH y el número de blastocistos (r=0.55 y r=0.6, r...
SPERMOVA
Seminal plasma proteins (SPP) are fundamental for oocyte fertilization by sperm cells. In bovine,... more Seminal plasma proteins (SPP) are fundamental for oocyte fertilization by sperm cells. In bovine, the structure and function of SPP have been widely described in several studies, where the spermadhesin family has been highlighted. Spermadhesin proteins are closely related to sperm motility and viability along with protecting the sperm cells against oxidative stress. Spermadhesin-1, also known as acidic Seminal Fluid Proteins (aSFP), exhibits a redox activity that protects the sperm cells from reactive oxygen species (ROS), an important feature that could be taken in advantage to improve the postthaw seminal quality of sperm cells after cryopreservation processes. Therefore, the aim of this research was to produce heterologous aSFP using Escherichia coli as a cell factory. For this purpose, the DNA sequence of aSFP was inserted into a pDAss plasmid, containing a six-histidine tag (6xhis). The obtained construct was used to transform BL21 (DE3) E. coli competent cells. The expression ...
SPERMOVA, 2021
Bovine livestock is one of the most important economic and social sectors for many countries. In ... more Bovine livestock is one of the most important economic and social sectors for many countries. In this sense, the development of strategies to improve reproductive bull fertility and reproduction rates is relevant. It's highlighted the role of seminal plasma proteins (SPP) in reproductive fertility, so it has found close relationships among studies on the structure and biological activity of SPP, with seminal quality, including viability, sperm motility, and morphology. In addition, they have been found to regulate sperm functions such as capacitation, acrosome reaction, and they are even related to protecting sperm against thermal and oxidative stress. Moreover, the methods of separation and protein identification and their contribution to characterizing the bovine SP proteome should be also highlighted. In this sense, the most recent studies have been directed towards developing supplements with SPP that improve quality sperm subjected to cryopreservation processes. Research ha...
Microbial cell factories, Jan 8, 2016
Production of recombinant drugs in process-friendly endotoxin-free bacterial factories targets to... more Production of recombinant drugs in process-friendly endotoxin-free bacterial factories targets to a lessened complexity of the purification process combined with minimized biological hazards during product application. The development of nanostructured recombinant materials in innovative nanomedical activities expands such a need beyond plain functional polypeptides to complex protein assemblies. While Escherichia coli has been recently modified for the production of endotoxin-free proteins, no data has been so far recorded regarding how the system performs in the fabrication of smart nanostructured materials. We have here explored the nanoarchitecture and in vitro and in vivo functionalities of CXCR4-targeted, self-assembling protein nanoparticles intended for intracellular delivery of drugs and imaging agents in colorectal cancer. Interestingly, endotoxin-free materials exhibit a distinguishable architecture and altered size and target cell penetrability than counterparts produced...
Revista MVZ Córdoba
This study was performed to evaluate the effect of the addition of proteins on the postthawing vi... more This study was performed to evaluate the effect of the addition of proteins on the postthawing viability of spermatozoa. Materials and methods. Spermatozoa were frozen with two different media: Citrate-fructose and Bioxcell®. The isolation of seminal plasma proteins of low molecular weight was performed through low pressure liquid chromatography. It was determined that the proteins of interest eluted in fractions 21-25, and two dimensional electrophoresis was performed. Thawed sperm was incubated at 37°C for one hour with 0.5, 1, 1.5 and 2.0 mg of 21-25 fraction protein. Two additional treatments were included: one with seminal plasma total protein, and another one without protein. Results. Two dimensional electrophoresis of protein confirmed the presence of two bands of 14 and 16 kDa and seven spots with iso-electric points between 5.0 - 5.5 respectively. Incubation of the spermatozoa with the 21-25 fraction showed that sperm viability increases by 20% with doses of 1 and 1.5 mg of...
Microbial Cell Factories, 2014
Background: Escherichia coli has been a main host for the production of recombinant proteins of b... more Background: Escherichia coli has been a main host for the production of recombinant proteins of biomedical interest, but conformational stress responses impose severe bottlenecks that impair the production of soluble, proteolytically stable versions of many protein species. In this context, emerging Generally Recognized As Safe (GRAS) bacterial hosts provide alternatives as cell factories for recombinant protein production, in which limitations associated to the use of Gram-negative microorganisms might result minimized. Among them, Lactic Acid Bacteria and specially Lactococcus lactis are Gram-positive GRAS organisms in which recombinant protein solubility is generically higher and downstream facilitated, when compared to E. coli. However, deep analyses of recombinant protein quality in this system are still required to completely evaluate its performance and potential for improvement. Results: We have explored here the conformational quality (through specific fluorescence emission) and solubility of an aggregation-prone GFP variant (VP1GFP) produced in L. lactis. In this context, our results show that parameters such as production time, culture conditions and growth temperature have a dramatic impact not only on protein yield, but also on protein solubility and conformational quality, that are particularly favored under fermentative metabolism. Conclusions: Metabolic regime and cultivation temperature greatly influence solubility and conformational quality of an aggregation-prone protein in L. lactis. Specifically, the present study proves that anaerobic growth is the optimal condition for recombinant protein production purposes. Besides, growth temperature plays an important role regulating both protein solubility and conformational quality. Additionally, our results also prove the great versatility for the manipulation of this bacterial system regarding the improvement of functionality, yield and quality of recombinant proteins in this species. These findings not only confirm L. lactis as an excellent producer of recombinant proteins but also reveal room for significant improvement by the exploitation of external protein quality modulators.
Applied Microbiology and Biotechnology, 2014
Escherichia coli is the workhorse for gene cloning and production of soluble recombinant proteins... more Escherichia coli is the workhorse for gene cloning and production of soluble recombinant proteins in both biotechnological and biomedical industries. The bacterium is also a good producer of several classes of protein-based self-assembling materials such as inclusion bodies (IBs). Apart from being a relatively pure source of protein for in vitro refolding, IBs are under exploration as functional, protein-releasing materials in regenerative medicine and protein replacement therapies. Endotoxin removal is a critical step for downstream applications of therapeutic proteins. The same holds true for IBs as they are often highly contaminated with cell-wall components of the host cells. Here we have investigated the production of IBs in a recently developed endotoxin-free E. coli strain. The characterization of IBs revealed this mutant as a very useful cell factory for the production of functional endotoxin-free IBs that are suitable for the use at biological interfaces without inducing endotoxic responses in human immune cells.
Revista de Investigaciones Veterinarias del Perú
El objetivo del estudio fue determinar mediante SDS PAGE el perfil de proteínas del plasma semina... more El objetivo del estudio fue determinar mediante SDS PAGE el perfil de proteínas del plasma seminal de toros criollos Romosinuano (ROMO) y Costeño con Cuernos (CCC) y su relación con los parámetros de calidad espermática en semen fresco y descongelado. Se colectaron tres eyaculados por toro mediante electro-eyaculación de 10 reproductores ROMO y 10 CCC. En semen fresco se determinó viabilidad (VF), motilidad masal (MMF), motilidad individual rápida progresiva (MIRPF) y concentración espermática (CE). El plasma seminal (PS) se obtuvo mediante doble centrifugación. En el semen descongelado se determinó motilidad individual de rápidos progresivos (MIRPPC), progresividad (PRPC), rápidos progresivos (RPPC) y medios progresivos (MPPC), en ambos casos usando el sistema de análisis computarizado CASA. Adicionalmente se determinó la viabilidad (VPC), e integridad de la membrana mediante el test hipoosmótico. Las proteínas se separaron por electroforesis en geles de poliacrilamida (SDS PAGE). ...
Ciencia y Agricultura
Los programas de reproducción y mejoramiento animal requieren la optimización de herramientas bio... more Los programas de reproducción y mejoramiento animal requieren la optimización de herramientas biotecnológicas capaces de favorecer los índices reproductivos en diversas especies. El uso de aditivos proteicos que mejoren la criopreservación espermática y la producción de embriones in vitro, parece ser una alternativa interesante. La Osteopontina se ha relacionado con el potencial fecundante del espermatozoide y con el desarrollo embrionario temprano. El objetivo de este trabajo fue determinar las condiciones óptimas para la producción de Osteopontina recombinante (rOPN) mediante el uso de Escherichia coli como fábrica celular. Para esto, el gen de la OPN se insertó en un vector de expresión pET28(a+) inducible por IPTG, con resistencia a la Kanamicina y una cola de histidinas (6xHis-tag). El constructo resultante se usó para transformar células competentes de E. Coli BL21-Star TM. Las colonias transformadas se usaron para la producción de rOPN-H6 a 20, 30 y 37 °C, probándose dos conc...
Revista MVZ Córdoba, 2013
RESUMENObjetivo. El objetivo de este trabajo fue evaluar el efecto de la adición de proteínas del... more RESUMENObjetivo. El objetivo de este trabajo fue evaluar el efecto de la adición de proteínas del plasma seminal sobre el porcentaje de espermatozoides bovinos viables post-descongelación. Materiales y métodos. Los espermatozoides se congelaron usando dos medios (citrato-fructosa-yema y Bioxcell®) y la obtención de proteínas de plasma seminal de bajo peso molecular se realizó por medio de cromatografía líquida de baja presión. Las proteínas de interés eluyeron en las fracciones 21-25 y se sometieron a electroforésis en una y dos dimensiones. Los espermatozoides se incubaron a 37°C durante una hora, con 0.5, 1.0, 1.5 y 2.0 mg de la fracción 21-25. Se incluyeron dos tratamientos adicionales: uno con proteínas totales del plasma seminal y otro sin proteína. Resultados. La electroforésis bidimensional de las fracciones confirmó la presencia de siete puntos de proteína de bajo peso molecular (14-16 kDa y punto Isoeléctrico de 5.0 - 5.5). La adición de estas proteínas aumentó 20% (p<0....
Revista Colombiana de Ciencias Pecuarias
Background: cryopreservation decreases sperm viability by approximately 50%. Objective: the objec... more Background: cryopreservation decreases sperm viability by approximately 50%. Objective: the objective of this study was to determine the effect of the addition of seminal plasma proteins on post-thawing sperm viability in Sanmartinero and Zebu semen. Methods: semen samples from 10 bulls of each breed were used, and seminal plasma was subjected to two-dimensional electrophoresis to establish the relationship between the relative amount of each protein spot and sperm viability. Then, seminal plasma was subjected to exclusion chromatography to separate the fraction containing these proteins. This fraction was added in doses of 0.5, 1.0, 1.5 and 2.0 mg, to 1 x 106. Sperm was thawed and incubated at 37 °C for 1 h to determine its effect on postthaw viability. Sperm were frozen using two media (citrate-fructose-yolk and Bioxcell®). Results: we found one protein spot (16.20 kDa, PI 5.5) in Sanmartinero seminal plasma that correlated (r = 0.64 p<0.001) with viability. This spot was found...
Microbial Cell Factories, 2016
Nanoscale, 2017
Self-assembling proteins are gaining attention as building blocks for application-tailored nanosc... more Self-assembling proteins are gaining attention as building blocks for application-tailored nanoscale materials.
Tropical Life Sciences Research
The sperm interacts with seminal plasma proteins during its transport through the female reproduc... more The sperm interacts with seminal plasma proteins during its transport through the female reproductive tract to reach the oocyte. Seminal plasma proteins have been associated as biomarkers of fertility in bovine males, while two-dimensional electrophoresis in polyacrylamide gels under denaturing conditions (2D-PAGE) is a useful technique for their separation, allowing their subsequent analysis with the aid of specialized software. Brahman bulls are known for their tolerance to tropical conditions such as low-quality pastures, high temperatures, and relative humidity as well as moderate resistance to infestations by parasites and insects. The present study describes the two-dimensional electrophoretic profiles of the seminal plasma proteins in the rainy and dry seasons, associating them with the fertility of Brahman bulls in the Colombian Orinoquía in a 90-days breeding season and a single-sire mating system (1 bull per 50 Brahman cows) with 60 consecutive days of rest. The fertility-...
Revista de Investigaciones Veterinarias del Perú
El objetivo del estudio fue comparar los niveles de la hormona antimülleriana (AMH) en hembras Br... more El objetivo del estudio fue comparar los niveles de la hormona antimülleriana (AMH) en hembras Brahman y Blanco Orejinegro donadoras de ovocitos y su relación con la reserva ovárica y producción de embriones in vitro. Se obtuvieron ovocitos de 42 hembras Brahman y 38 Blanco Orejinegro mediante punción ovárica guiada por ultrasonido (OPU). Se colectaron muestras de sangre previo a la OPU para la determinación de las concentraciones séricas de AMH. Los ovocitos y embriones se cultivaron de manera individual para cada donante. Los resultaron mostraron que las concentraciones séricas de AMH fueron de 0.78 ± 0.34 ng/ml (0.09-1.89 ng/ml) para las vacas Brahman y de 0.72 ± 0.32 ng/ml (0.13-1.19 ng/ml) para las Blanco Orejinegro. La correlación entre la concentración de AMH y el número de folículos fue de r=0.77 y r=0.74 para las vacas Brahman y Blanco Orejinegro, respectivamente., así como una correlación positiva entre la concentración de AMH y el número de blastocistos (r=0.55 y r=0.6, r...
SPERMOVA
Seminal plasma proteins (SPP) are fundamental for oocyte fertilization by sperm cells. In bovine,... more Seminal plasma proteins (SPP) are fundamental for oocyte fertilization by sperm cells. In bovine, the structure and function of SPP have been widely described in several studies, where the spermadhesin family has been highlighted. Spermadhesin proteins are closely related to sperm motility and viability along with protecting the sperm cells against oxidative stress. Spermadhesin-1, also known as acidic Seminal Fluid Proteins (aSFP), exhibits a redox activity that protects the sperm cells from reactive oxygen species (ROS), an important feature that could be taken in advantage to improve the postthaw seminal quality of sperm cells after cryopreservation processes. Therefore, the aim of this research was to produce heterologous aSFP using Escherichia coli as a cell factory. For this purpose, the DNA sequence of aSFP was inserted into a pDAss plasmid, containing a six-histidine tag (6xhis). The obtained construct was used to transform BL21 (DE3) E. coli competent cells. The expression ...
SPERMOVA, 2021
Bovine livestock is one of the most important economic and social sectors for many countries. In ... more Bovine livestock is one of the most important economic and social sectors for many countries. In this sense, the development of strategies to improve reproductive bull fertility and reproduction rates is relevant. It's highlighted the role of seminal plasma proteins (SPP) in reproductive fertility, so it has found close relationships among studies on the structure and biological activity of SPP, with seminal quality, including viability, sperm motility, and morphology. In addition, they have been found to regulate sperm functions such as capacitation, acrosome reaction, and they are even related to protecting sperm against thermal and oxidative stress. Moreover, the methods of separation and protein identification and their contribution to characterizing the bovine SP proteome should be also highlighted. In this sense, the most recent studies have been directed towards developing supplements with SPP that improve quality sperm subjected to cryopreservation processes. Research ha...
Microbial cell factories, Jan 8, 2016
Production of recombinant drugs in process-friendly endotoxin-free bacterial factories targets to... more Production of recombinant drugs in process-friendly endotoxin-free bacterial factories targets to a lessened complexity of the purification process combined with minimized biological hazards during product application. The development of nanostructured recombinant materials in innovative nanomedical activities expands such a need beyond plain functional polypeptides to complex protein assemblies. While Escherichia coli has been recently modified for the production of endotoxin-free proteins, no data has been so far recorded regarding how the system performs in the fabrication of smart nanostructured materials. We have here explored the nanoarchitecture and in vitro and in vivo functionalities of CXCR4-targeted, self-assembling protein nanoparticles intended for intracellular delivery of drugs and imaging agents in colorectal cancer. Interestingly, endotoxin-free materials exhibit a distinguishable architecture and altered size and target cell penetrability than counterparts produced...
Revista MVZ Córdoba
This study was performed to evaluate the effect of the addition of proteins on the postthawing vi... more This study was performed to evaluate the effect of the addition of proteins on the postthawing viability of spermatozoa. Materials and methods. Spermatozoa were frozen with two different media: Citrate-fructose and Bioxcell®. The isolation of seminal plasma proteins of low molecular weight was performed through low pressure liquid chromatography. It was determined that the proteins of interest eluted in fractions 21-25, and two dimensional electrophoresis was performed. Thawed sperm was incubated at 37°C for one hour with 0.5, 1, 1.5 and 2.0 mg of 21-25 fraction protein. Two additional treatments were included: one with seminal plasma total protein, and another one without protein. Results. Two dimensional electrophoresis of protein confirmed the presence of two bands of 14 and 16 kDa and seven spots with iso-electric points between 5.0 - 5.5 respectively. Incubation of the spermatozoa with the 21-25 fraction showed that sperm viability increases by 20% with doses of 1 and 1.5 mg of...
Microbial Cell Factories, 2014
Background: Escherichia coli has been a main host for the production of recombinant proteins of b... more Background: Escherichia coli has been a main host for the production of recombinant proteins of biomedical interest, but conformational stress responses impose severe bottlenecks that impair the production of soluble, proteolytically stable versions of many protein species. In this context, emerging Generally Recognized As Safe (GRAS) bacterial hosts provide alternatives as cell factories for recombinant protein production, in which limitations associated to the use of Gram-negative microorganisms might result minimized. Among them, Lactic Acid Bacteria and specially Lactococcus lactis are Gram-positive GRAS organisms in which recombinant protein solubility is generically higher and downstream facilitated, when compared to E. coli. However, deep analyses of recombinant protein quality in this system are still required to completely evaluate its performance and potential for improvement. Results: We have explored here the conformational quality (through specific fluorescence emission) and solubility of an aggregation-prone GFP variant (VP1GFP) produced in L. lactis. In this context, our results show that parameters such as production time, culture conditions and growth temperature have a dramatic impact not only on protein yield, but also on protein solubility and conformational quality, that are particularly favored under fermentative metabolism. Conclusions: Metabolic regime and cultivation temperature greatly influence solubility and conformational quality of an aggregation-prone protein in L. lactis. Specifically, the present study proves that anaerobic growth is the optimal condition for recombinant protein production purposes. Besides, growth temperature plays an important role regulating both protein solubility and conformational quality. Additionally, our results also prove the great versatility for the manipulation of this bacterial system regarding the improvement of functionality, yield and quality of recombinant proteins in this species. These findings not only confirm L. lactis as an excellent producer of recombinant proteins but also reveal room for significant improvement by the exploitation of external protein quality modulators.
Applied Microbiology and Biotechnology, 2014
Escherichia coli is the workhorse for gene cloning and production of soluble recombinant proteins... more Escherichia coli is the workhorse for gene cloning and production of soluble recombinant proteins in both biotechnological and biomedical industries. The bacterium is also a good producer of several classes of protein-based self-assembling materials such as inclusion bodies (IBs). Apart from being a relatively pure source of protein for in vitro refolding, IBs are under exploration as functional, protein-releasing materials in regenerative medicine and protein replacement therapies. Endotoxin removal is a critical step for downstream applications of therapeutic proteins. The same holds true for IBs as they are often highly contaminated with cell-wall components of the host cells. Here we have investigated the production of IBs in a recently developed endotoxin-free E. coli strain. The characterization of IBs revealed this mutant as a very useful cell factory for the production of functional endotoxin-free IBs that are suitable for the use at biological interfaces without inducing endotoxic responses in human immune cells.
Revista de Investigaciones Veterinarias del Perú
El objetivo del estudio fue determinar mediante SDS PAGE el perfil de proteínas del plasma semina... more El objetivo del estudio fue determinar mediante SDS PAGE el perfil de proteínas del plasma seminal de toros criollos Romosinuano (ROMO) y Costeño con Cuernos (CCC) y su relación con los parámetros de calidad espermática en semen fresco y descongelado. Se colectaron tres eyaculados por toro mediante electro-eyaculación de 10 reproductores ROMO y 10 CCC. En semen fresco se determinó viabilidad (VF), motilidad masal (MMF), motilidad individual rápida progresiva (MIRPF) y concentración espermática (CE). El plasma seminal (PS) se obtuvo mediante doble centrifugación. En el semen descongelado se determinó motilidad individual de rápidos progresivos (MIRPPC), progresividad (PRPC), rápidos progresivos (RPPC) y medios progresivos (MPPC), en ambos casos usando el sistema de análisis computarizado CASA. Adicionalmente se determinó la viabilidad (VPC), e integridad de la membrana mediante el test hipoosmótico. Las proteínas se separaron por electroforesis en geles de poliacrilamida (SDS PAGE). ...
Ciencia y Agricultura
Los programas de reproducción y mejoramiento animal requieren la optimización de herramientas bio... more Los programas de reproducción y mejoramiento animal requieren la optimización de herramientas biotecnológicas capaces de favorecer los índices reproductivos en diversas especies. El uso de aditivos proteicos que mejoren la criopreservación espermática y la producción de embriones in vitro, parece ser una alternativa interesante. La Osteopontina se ha relacionado con el potencial fecundante del espermatozoide y con el desarrollo embrionario temprano. El objetivo de este trabajo fue determinar las condiciones óptimas para la producción de Osteopontina recombinante (rOPN) mediante el uso de Escherichia coli como fábrica celular. Para esto, el gen de la OPN se insertó en un vector de expresión pET28(a+) inducible por IPTG, con resistencia a la Kanamicina y una cola de histidinas (6xHis-tag). El constructo resultante se usó para transformar células competentes de E. Coli BL21-Star TM. Las colonias transformadas se usaron para la producción de rOPN-H6 a 20, 30 y 37 °C, probándose dos conc...
Revista MVZ Córdoba, 2013
RESUMENObjetivo. El objetivo de este trabajo fue evaluar el efecto de la adición de proteínas del... more RESUMENObjetivo. El objetivo de este trabajo fue evaluar el efecto de la adición de proteínas del plasma seminal sobre el porcentaje de espermatozoides bovinos viables post-descongelación. Materiales y métodos. Los espermatozoides se congelaron usando dos medios (citrato-fructosa-yema y Bioxcell®) y la obtención de proteínas de plasma seminal de bajo peso molecular se realizó por medio de cromatografía líquida de baja presión. Las proteínas de interés eluyeron en las fracciones 21-25 y se sometieron a electroforésis en una y dos dimensiones. Los espermatozoides se incubaron a 37°C durante una hora, con 0.5, 1.0, 1.5 y 2.0 mg de la fracción 21-25. Se incluyeron dos tratamientos adicionales: uno con proteínas totales del plasma seminal y otro sin proteína. Resultados. La electroforésis bidimensional de las fracciones confirmó la presencia de siete puntos de proteína de bajo peso molecular (14-16 kDa y punto Isoeléctrico de 5.0 - 5.5). La adición de estas proteínas aumentó 20% (p<0....
Revista Colombiana de Ciencias Pecuarias
Background: cryopreservation decreases sperm viability by approximately 50%. Objective: the objec... more Background: cryopreservation decreases sperm viability by approximately 50%. Objective: the objective of this study was to determine the effect of the addition of seminal plasma proteins on post-thawing sperm viability in Sanmartinero and Zebu semen. Methods: semen samples from 10 bulls of each breed were used, and seminal plasma was subjected to two-dimensional electrophoresis to establish the relationship between the relative amount of each protein spot and sperm viability. Then, seminal plasma was subjected to exclusion chromatography to separate the fraction containing these proteins. This fraction was added in doses of 0.5, 1.0, 1.5 and 2.0 mg, to 1 x 106. Sperm was thawed and incubated at 37 °C for 1 h to determine its effect on postthaw viability. Sperm were frozen using two media (citrate-fructose-yolk and Bioxcell®). Results: we found one protein spot (16.20 kDa, PI 5.5) in Sanmartinero seminal plasma that correlated (r = 0.64 p<0.001) with viability. This spot was found...
Microbial Cell Factories, 2016
Nanoscale, 2017
Self-assembling proteins are gaining attention as building blocks for application-tailored nanosc... more Self-assembling proteins are gaining attention as building blocks for application-tailored nanoscale materials.