• Asian-Australasian Journal of Animal Sciences
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• v.24 no.9
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• pp.1274-1281
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• 2011

Dietary protein restriction affects lipid metabolism in rats. This study was performed to determine the effect of a low protein diet on hepatic lipid metabolism and insulin sensitivity in growing male rats. Growing rats were fed either a control 20% protein diet or an 8% low protein diet. Feeding a low protein diet for four weeks from 8 weeks of age induced a fatty liver. Expression of acetyl-CoA carboxylase, a key lipogenic enzyme, was increased in rats fed a low protein diet. Feeding a low protein diet decreased very low density lipoprotein (VLDL) secretion without statistical significance. Feeding a low protein diet down-regulated protein expression of microsomal triglyceride transfer protein, an important enzyme of VLDL secretion. Feeding a low protein diet increased serum adiponectin levels. We performed glucose tolerance test (GTT) and insulin tolerance test (ITT). Both GTT and ITT were increased in protein-restricted growing rats. Our results demonstrate that dietary protein restriction increases insulin sensitivity and that this could be due to low-protein diet-mediated metabolic adaptation. In addition, increased adiponectin levels may influences insulin sensitivity. In conclusion, dietary protein restriction induces a fatty liver. Both increased lipogenesis and decreased VLDL secretion has contributed to this metabolic changes. In addition, insulin resistance was not associated with fatty liver induced by protein restriction.

• Food Science and Preservation
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• v.15 no.6
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• pp.903-908
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• 2008

This study investigated protein changes in soymilk and whole soymilk due to enzymatic hydrolysis. The total free amino acid contents of low molecular weight soymilk (LSM) and low molecular weight whole soymilk (LWSM) were higher than soymilk (SM) and whole soymilk (WSM). The essential amino acid content was similar in SM and LSM, but was higher in LWSM than WSM. In SDS-PAGE performed to tendency of becoming low molecules, the soy protein molecular weights were 3372 kDa for SM and WSM, but 17 kDa or less for LSM and LWSM. Also, high molecular weight protein spots were evident in 2-D electrophoresis of SM and LSM, but only low molecular weight protein spots of various sizes were evident in WSM and LWSM. This suggests that the high molecular weight protein in SM and WSM is changed to low molecular weight protein by enzymatic hydrolysis. Further investigations of the separation and qualities of these proteins are required.

• Animal Bioscience
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• v.34 no.10
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• pp.1600-1606
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• 2021

Objective: This study was conducted to enhance our understanding of nitrogen (N) metabolism and mammary amino acid (AA) utilization in lactating cows with divergent phenotypes of residual feed intake (RFI). Methods: Fifty-three multiparous mid-lactation Holstein dairy cows were selected for RFI measurements over a 50-d experimental period. The 26 cows with the most extreme RFI values were classified into the high RFI (n = 13) and low RFI (n = 13) groups, respectively, for analysis of N metabolism and AA utilization. Results: Compared with the high RFI cows, the low RFI animals had lower dry matter intake (p<0.01) with no difference observed in milk yield between the two groups (p>0.10). However, higher ratios of milk yield to dry matter intake (p<0.01) were found in the low RFI cows than in the high RFI cows. The low RFI cows had significant greater ratios of milk protein to metabolizable protein (p = 0.02) and milk protein to crude protein intake than the high RFI cows (p = 0.01). The arterial concentration and mammary uptake of essential AA (p<0.10), branched-chain AA (p<0.10), and total AA (p<0.10) tended to be lower in the low RFI cows. Additionally, the low RFI cows tended to have a lower ratio of AA uptake to milk output for essential AA (p = 0.08), branched-chain AA (p = 0.07) and total AA (p = 0.09) than the high RFI cows. Conclusion: In summary, both utilization of metabolizable protein for milk protein and mammary AA utilization are more efficient in cows with lower RFI than in the high RFI cows. Our results provide new insight into the protein metabolic processes (related to N and AA) involved in feed efficiency.

• Parasites, Hosts and Diseases
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• v.41 no.2
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• pp.121-123
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• 2003

This study was designed to detect and evaluate an antigenicity of low molecular weight proteins of Fasciola hepatica in fascioliasis. Low molecular weight protein of F. hepatica was purified by ammonium sulfate precipitation and Sephacryl S-100 HR gel filtration. The protein obtained was estimated to be 8 kDa on 7.5-15% gradient sodium dodecyl sulfate gel electrophoresis. Immunoblotting studies showed that the 8 kDa protein reacted with human fascioliasis sera, but not other trematodiasis sera. This result suggests that the 8 kDa protein of F. hepatica is one of diagnostic antigens in human fascioliasis without cross-reaction with other human trematodiasis.

• Proceedings of the Botanical Society of Korea Conference
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• 1999.04a
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• pp.18-18
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• 1999

We characterized a cDNA clone for a low molecular weight heat-shock protein (LMW HSP) from tobacco named TLHS-l. Nucleotide sequence determination of TLHS-1 identified an open reading frame for 159 amino acids. To the upstream of the open reading frame, a sequence of 124 nucleotides was determined. To the 3' downstream of the open reading frame, 212 nucleotides were identified which carried poly(A)-tail. Comparison of the open reading frame and hydropathy plot of TLHS-1 with the previously reported class I LMW HSPs showed high identity which classified TLHS-1 as a class I LMW HSP cDNA clone. We proposed that there are six consensus regions in class I LMW HSPs. RNA blot hybridization for TLHS-1 showed a typical expression pattern of heat-shock-inducible gene from three common tobacco cultivars. The open reading frame of TLHS-1 was overexpressed in Escherichia coli. TLHS-1 protein confers thermal protection of other proteins in vitro and in vivo. Thermal induced aggregation of citrate synthase was reduced by purified TLHS-1 protein, and thermal death rate at $50^{\circ}C$ was reduced in E. coli expressing TLHS-l. From these data, we can expect that TLHS-1 acts as a molecular chaperone.perone.

• BMB Reports
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• v.57 no.4
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• pp.182-187
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• 2024

Neural stem cells (NSCs) in the adult hippocampus divide infrequently; the endogenous molecules modulating adult hippocampal neurogenesis (AHN) remain largely unknown. Here, we show that ErbB3 binding protein 1 (Ebp1), which plays important roles in embryonic neurodevelopment, acts as an essential modulator of adult neurogenic factors. In vivo analysis of Ebp1 neuron depletion mice showed impaired AHN with a low number of hippocampal NSCs and neuroblasts. Ebp1 leads to transcriptional repression of Bmp4 and suppression of Ascl1 promoter methylation in the dentate gyrus of the adult hippocampus reflecting an unusually high level of Bmp4 and low Ascl1 level in neurons of Ebp1-deficient mice. Therefore, our findings suggests that Ebp1 could act as an endogenous modulator of the interplay between Bmp4 and Ascl1/Notch signaling, contributing to AHN.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.23 no.1
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• pp.1-4
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• 1978

The change of soluble protein components in leaf discoloration of rice plant was investigated in the Growth Cabinet with various temperature conditions. The ratio between high molecular soluble protein and low molecular soluble protein was high under high temperature condition, while low under low temperature condition, and also lower in Indica type varieties than Japonica type variety.

• Molecules and Cells
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• v.43 no.12
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• pp.1035-1045
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• 2020

The Drosophila genome contains four low molecular weight-protein tyrosine phosphatase (LMW-PTP) members: Primo-1, Primo-2, CG14297, and CG31469. The lack of intensive biochemical analysis has limited our understanding of these proteins. Primo-1 and CG31469 were previously classified as pseudophosphatases, but CG31469 was also suggested to be a putative protein arginine phosphatase. Herein, we present the crystal structures of CG31469 and Primo-1, which are the first Drosophila LMW-PTP structures. Structural analysis showed that the two proteins adopt the typical LMW-PTP fold and have a canonically arranged P-loop. Intriguingly, while Primo-1 is presumed to be a canonical LMW-PTP, CG31469 is unique as it contains a threonine residue at the fifth position of the P-loop motif instead of highly conserved isoleucine and a characteristically narrow active site pocket, which should facilitate the accommodation of phosphoarginine. Subsequent biochemical analysis revealed that Primo-1 and CG31469 are enzymatically active on phosphotyrosine and phosphoarginine, respectively, refuting their classification as pseudophosphatases. Collectively, we provide structural and biochemical data on two Drosophila proteins: Primo-1, the canonical LMW-PTP protein, and CG31469, the first investigated eukaryotic protein arginine phosphatase. We named CG31469 as DARP, which stands for Drosophila ARginine Phosphatase.

• Bulletin of the Korean Chemical Society
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• v.32 no.4
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• pp.1315-1320
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• 2011

Whey protein (WP) is a mixture of proteins, and is of high nutritional values. WP has become an important source of functional ingredients in various health-promoting foods. In this study, size-exclusion chromatography (SEC) and asymmetrical flow field-flow fractionation (AsFlFFF) were used for separation and analysis of whey proteins. It was found that a lab-prepared WP from raw milk is mostly of ${\beta}$-lactoglobulin with small amount of higher molecular weight components, while a commercial whey protein isolate (WPI) powder contains relatively larger amount of components other than ${\beta}$-lactoglobulin, including IgG and protein aggregates. Results suggest that AsFlFFF provides higher resolution for the major whey proteins than SEC in their normal operation conditions. AsFlFFF could differentiate the BSA and Albumin, despite a small difference in their molecular weights, and also was able to separate much smaller amount of aggregates from monomers. It is noted that SEC was able to show the presence of low molecular weight components other than the major whey proteins in the WP samples, which AsFlFFF could not show, probably due to the partial loss of those low molecular weight species through the membrane.

• Molecules and Cells
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• v.25 no.3
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• pp.446-451
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• 2008

We assessed heterologous protein expression in 64 strains obtained from the Escherichia coli Reference (ECOR) collection, a collection representing diverse natural E. coli populations. A plasmid generating a glutathione S-transferase and plant carbonic anhydrase fusion protein (GST-CA) under the control of the tac promoter was introduced into the ECOR strains, and the quantity of the fusion protein was determined by SDS-PAGE. The foreign protein was generated at various levels, from very high (40 strains, high producers) to very low (six strains, low producers). Immunoblotting showed that the high producers expressed approximately 250-500 times more GST-CA protein than the low producers. The results of semi-quantitative RT-PCR showed that the low producers generated mRNA levels comparable to those of the high producers, thereby suggesting that, at least in this case, inefficient translation is a major cause of the low production. We introduced a different plasmid, which expressed a maltose binding protein and plant guanylate kinase fusion protein (MBP-GK) into the six low producers. Interestingly, five of these expressed MBP-GK at very high levels. Thus, we conclude that the production of a particular protein from an expression vector can vary considerably, depending on the host strain. Strains in the ECOR collection could function as useful alternative hosts when a desired level of protein expression is not obtained from commonly used strains, such as E. coli K12 or B derivatives.