• Reproductive and Developmental Biology
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• v.31 no.3
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• pp.133-137
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• 2007

The objective of the study was to determine the relationship between the mRNA expression levels of sperm phospholipids hydroperoxide glutathione peroxidase (PHGPx) and heparin-binding protein (HBP), and in-vivo fertility in boars. The farrowing rate was not correlated with litter size. Sperm PHGPx mRNA expression level of the larger litter size (over 10) group $(2,414.7{\pm}400.7)$ was high that of smaller litter size (below 8) group $(1,875.8{\pm}311.2)$. Sperm HBP mRNA expression level was also higher in the larger litter size $(2,255.9{\pm}360.8)$ group than the smaller litter size $(2,155.4{\pm}378.0)$. However, significant differences were not observed. Sperm PHGPx mRNA level was correlated positively with litter size (r=0.206). Because the expression levels of PHGPx and HBP are not strongly correlated with in-vivo fertility, PHGPx and HBP can not be considered a predictive measure for fertility in boars.

• Preventive Nutrition and Food Science
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• v.3 no.2
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• pp.133-142
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• 1998

Effects of protein heat treatment and surfactant additionoo the orthokindetic stability of $\beta$-lactoglobulin-stabilized emulsions have been investigated under turbulent flow conditions. In studies on protein-stabilized emulsions, samples which had been subjected to heat treatment(i.e. the protein solution orthe emulsion) have been found to be more prone to orthokinetic coalescene than the untreated ones. The emulsions stabilized with protein heated above the denaturation temperature(i.e. 7$0^{\circ}C$) showed the bigger initial average droplet size, which resulted in an increased orthokinetic coalescenece rate. The storage of the protein-stabilized emulsion at high temperature prior to the shearing experiment also made the emulsion less stable in the shear field. Interestingly. the addition of DATEM has been found to produce a substantial increase in orthokinetic stability of the heat-denatured protein-stabilized emulsion system, although Tween 20 is the opposite case.

• Journal of Dairy Science and Biotechnology
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• v.40 no.3
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• pp.134-142
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• 2022

Protein-enriched dairy powder is widely consumed to promote muscle synthesis. Recently, in Korea, elderly people have also begun consuming protein powder products to prevent muscle loss. However, these protein-enriched powders have poor flowability and hydration properties because of the fine particles of spray-dried milk protein powder. Therefore, in this study, the fluidized bed agglomeration process was used to solve these problems. The rheological and physical properties of milk protein isolate (MPI)/skim milk powder (SMP) mixtures were effectively improved via fluidized bed agglomeration. The particle size of the MPI/SMP mixtures significantly increased from 35.7-58 ㎛ to 118-136 ㎛, the flowability level improved from fair (21.4-26.3) to good (15.7-16.3), and the cohesiveness level changed from intermediate (1.27-1.36) to low (1.18-1.19) after fluidized bed agglomeration. In addition, the wetting time of the agglomerated MPI/SMP mixtures was effectively reduced to 4.67-58.3 s by fluidized bed agglomeration. These findings may be useful for manufacturing protein-enriched dairy powders with good instant properties.

• Journal of Plant Biotechnology
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• v.1 no.1
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• pp.13-19
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• 1999

The visco-elastic properties of gluten are major determinants of the processing properties of doughs. These visco-elastic properties are strongly influenced by the ratio of monomeric and polymeric proteins and the size distribution of the polymeric proteins, which make up the gluten fraction of the dough. Recent studies have revealed that other features, such as the number of the cysteine residues of the HMW-GS, also play an important role in determining the functional characteristics. To modify the processing properties at molecular level, the relationship between the structure of molecules and dough properties has to be understood. In order to explore the relationships between individual proteins and dough properties, we have developed procedures for incorporating bacterially expressed proteins into doughs, and measuring their functional properties in small-scale equipment. A major problem in investigating the structure/function relationships of individual seed storage proteins is to obtain sufficient amounts of pure polypeptides from the complex families of proteins expressed in the endosperm. Therefore, we have established a simplified model system in which we produce specific protein genes through bacterial expression and test their functional properties in smallscale apparatus after incorporation into base flour. An S poor protein gene has been chosen as a template gene. This template gene has been modified using standard recombinant DNA techniques in order to test the effects of varying the number and position of cysteine residues, and the size of the protein. Doughs have been mixed in small scale apparatus and characterized with respect to their polymeric composition and their functional properties, including dough mixing, extensibility and small scale bating. We conclude that dough characteristics can be manipulated in a predictable manner by altering the cysteine residues and the size of high molecular weight glutenins.

• Journal of Microbiology and Biotechnology
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• v.17 no.8
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• pp.1236-1241
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• 2007

Five fusion proteins between Z domains derived from Staphylococcal Protein A and Green Fluorescent Protein or Human Proinsulin were produced on the periplasm of Escherichia coli. The effects of the molecular weight and amino acid composition of the translocated peptide, culture medium composition, and growth phase of the bacterial culture were analyzed regarding the expression and periplasmic secretion of the recombinant proteins. It was found that secretion was not affected by the size of the translocated peptide (17-42 kDa) and that the highest periplasmic production values were obtained on the exponential phase of growth. Moreover, the highest periplasmic values were obtained in minimal medium, showing the relevance of the culture medium composition on secretion. In silico prediction analysis suggested that with respect to the five proteins used in this study, those that are prone to form ${\alpha}$-helix structures are more translocated to the periplasm.

• KSBB Journal
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• v.6 no.3
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• pp.299-307
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• 1991

In this paper the effect of light on non-aerated Baker's Yeast(Saccharomyces cereuisiae) production and the protein excretion to the extracellular fluid is studied. Previous results in our laboratory indicate that at pH=5 and T-32$^{\circ}C$ yeast may be affected by light, but those differences seem to be within statistical variation of the data. In this paper, cell and extracellular protein concentrations along with redox potential are monitored for batch fermentations in the presence and absence of light at pH levels of 3 and 5 and at 31$^{\circ}C$, in order to explore whether possible light effects can be more readily discerned at lower pH values. Yeast particle size distributions are also determined over the course of fermentation using a particle counter in order to add one more measuring tool to our usual cell and total protein measurements. An apparently noticeable difference in the redox potential is observed between the light and the dark runs for early times for the pH=3 runs. The particle size distributions show differences in the particle diameters between light and dark runs at pH=3, but those differences fall within one standard deviation of the mean particle diameters.

• Journal of Dairy Science and Biotechnology
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• v.36 no.2
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• pp.121-124
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• 2018

Ellagic acid (EA) is a naturally occurring polyphenolic compound in vegetables, nuts, and fruits such as berries. EA has antioxidant, anticancer, anti-allergy, and anti-inflammatory activities. The objectives of this research were to investigate the physicochemical properties of nanoparticles before and after nano-encapsulation of EA in dairy protein and to develop a functional (anti-inflammatory) dairy protein-based beverage containing EA. A particle size analyzer was used to determine the physicochemical and morphological properties. High performance liquid chromatography was used to evaluate the entrapment efficiency of EA. The nanoparticles containing EA were 100 to 200 nm in diameter. The determined poly dispersity index value of 0.3 to 0.4 indicated that the nanoparticles were uniformly distributed with similar size. Zeta-potential values were also similar between the control groups. The entrapment efficiency of EA was nearly 90%. The results indicate the potential for development of nanoparticles containing EA beverage products with anti-inflammatory activity.

• Journal of Aquaculture
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• v.6 no.1
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• pp.13-27
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• 1993

In order to determine the protein requirements of the Korean rockfish Sebastes schlegeli six isocaloric diets containing crude protein level from 20\%\;to\;60\%$ were fed to two groups of fish, small and large size, with the initial average body weight of 8 g and 220 g respectively. White fish meal was used as a sole protein source. Daily weight gain, daily protein retention. daily energy retention, feed efficiency, protein retention efficiency and energy retention efficiency were significantly affected by the dietary protein content (p< 0.05). The growth parameters (that is, daily weight gain, daily protein retention and daily energy retention) increased up to $44\%$ protein level with no additional response above this point. The protein requirements were determined from daily weight gain using two different mathematical models. Second order polynomial regression analysis showed that maximum daily weight gain occurred at $56.7\%\;and\;50.6\%$ protein levels for the small size group and the large size group, respectively. However the protein requirements, determined by the broken line model, appeared to be about $40\%$ for both groups. Nutrient utilization also suggested that the protein requirements of both groups were close to $40\%$. When daily protein intake was considered, daily protein requirements per 100g of fish, estimated by the broken line model, were 0.99g and 0.35g for the small and large size groups respectively. Based on these results, a $40\%$ dietary crude protein level could be recommended for the optimum growth and efficient nutrient utilization of the Korean rockfish weighing between 8g and 300g.

• Korean Journal of Computational Design and Engineering
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• v.20 no.4
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• pp.321-327
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• 2015

In the protein database search, 3D structural shape comparison for protein screening plays a important role. Protein databases have big size and have been grown rapidly. Exhaustive search methods cannot provide a satisfactory performance. As protein is composed of a set of spheres, the similarity calculation of two set of spheres is very expensive. Thus, a reasonable filtering method could be an answer for the speedup of protein screening. In this paper, we suggest a speedup method for protein screening with atom number and bounding sphere. We also show some experimental results for the validity of our method.

• Animal cells and systems
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• v.6 no.4
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• pp.311-315
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• 2002

The RAD4 gene is essential for nucleotide excision repair in Saccharomyces cerevisiae. It has been known that the deduced amino acid sequence of Rad4 protein contains three DNA-dependent ATPase/helicase motifs. To determine the biochemical activities and functional role of RAD4 the Rad4 protein was expressed and purified. Immunoblot analysis showed a specific band of 21 kDa, which was well-matched with the size of open reading frame of the RAD4 gene. The purified Rad4 protein had no detectable helicase activity. However, the protein could interact with double stranded oligonucleotides, as judged by mobility shift assay. This result suggests that the Rad4 protein is a DNA binding protein.