Relationship between Molecular Structure Characteristics of Feed Proteins and Protein In vitro Digestibility and Solubility

Bai, Mingmei,Qin, Guixin,Sun, Zewei,Long, Guohui Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.8

The nutritional value of feed proteins and their utilization by livestock are related not only to the chemical composition but also to the structure of feed proteins, but few studies thus far have investigated the relationship between the structure of feed proteins and their solubility as well as digestibility in monogastric animals. To address this question we analyzed soybean meal, fish meal, corn distiller's dried grains with solubles, corn gluten meal, and feather meal by Fourier transform infrared (FTIR) spectroscopy to determine the protein molecular spectral band characteristics for amides I and II as well as ${\alpha}$-helices and ${\beta}$-sheets and their ratios. Protein solubility and in vitro digestibility were measured with the Kjeldahl method using 0.2% KOH solution and the pepsin-pancreatin two-step enzymatic method, respectively. We found that all measured spectral band intensities (height and area) of feed proteins were correlated with their the in vitro digestibility and solubility ($p{\leq}0.003$); moreover, the relatively quantitative amounts of ${\alpha}$-helices, random coils, and ${\alpha}$-helix to ${\beta}$-sheet ratio in protein secondary structures were positively correlated with protein in vitro digestibility and solubility ($p{\leq}0.004$). On the other hand, the percentage of ${\beta}$-sheet structures was negatively correlated with protein in vitro digestibility (p<0.001) and solubility (p = 0.002). These results demonstrate that the molecular structure characteristics of feed proteins are closely related to their in vitro digestibility at 28 h and solubility. Furthermore, the ${\alpha}$-helix-to-${\beta}$-sheet ratio can be used to predict the nutritional value of feed proteins.

A biothiols and H 2 O 2 responsive fluorescence probe for selective cancer imaging

Yin Nan,Qin Guixin,Wang Yuting,Tang Jiali,Yao Xin,Xu Qingling 대한화학회 2024 Bulletin of the Korean Chemical Society Vol.45 No.3

Identification of cancer from normal tissues is important for early diagnosis of cancer. Combined detection of multiple tumor markers is important for accurate diagnosis. It is urgent to develop fluorescent probes that are responsive to multiple cancer characterizations for selective cancer imaging. Herein, we designed a novel near‐infrared (NIR) fluorescent probe ( IRAPA ) using a hemi‐cyanine skeleton as fluorophore and 3‐acrylamidopropanoic ester as recognizing unit that is responsive to both oxidative and reductive molecules. IRAPA has faint fluorescence emission as the intramolecular charge transfer (ICT) process is blocked. H 2 O 2 , glutathione (GSH) and cysteine (Cys) can individually induce the hydrolysis of ester bond and give fluorescent NIR IROH . IRAPA shows low cytotoxicity and produces strong fluorescence specifically in cancer cells/tissues. While the normal cells/tissues showed very weak fluorescence. Moreover, IRAPA shows higher differences between cancer and normal cells compared to probes that only response to biothiols or ROS. Identification of cancer from normal tissues is important for early diagnosis of cancer. Combined detection of multiple tumor markers is important for accurate diagnosis. It is urgent to develop fluorescent probes that are responsive to multiple cancer characterizations for selective cancer imaging. Herein, we designed a novel near-infrared (NIR) fluorescent probe (IRAPA) using a hemicyanine skeleton as fluorophore and 3-acrylamidopropanoic ester as recognizing unit that is responsive to both oxidative and reductive molecules. IRAPA has faint fluorescence emission as the intramolecular charge transfer (ICT) process is blocked. H2O2, glutathione (GSH) and cysteine (Cys) can individually induce the hydrolysis of ester bond and give fluorescent NIR IROH. IRAPA shows low cytotoxicity and produces strong fluorescence specifically in cancer cells/tissues. While the normal cells/tissues showed very weak fluorescence. Moreover, IRAPA shows higher differences between cancer and normal cells compared to probes that only response to biothiols or ROS.

BEFS-PPARγ2 Cells Incubated with trans-11 C18:1 Exhibit More Beneficial Fatty Acid Synthesis

Tao Wang,이홍구,LiFang Wu,GuiXin Qin,Yujie Lou,Zewei Sun,Wei Guo,Jian Yang 한국식품과학회 2015 Food Science and Biotechnology Vol.24 No.5

Responses of the PPARγ2 (an adipogenic lineage determinant) over-expressed immortalized bovine embryonic fibroblast cell line (BEFS-PPARγ2 cells) to trans-11 C18:1 (TVA) incubation were evaluated. BEFS-PPARγ2 cells were well differentiated. Stearoyl-CoA desaturase 1, an endoplasmic reticulum enzyme that can catalyze conversion of TVA into cis-9, trans-11 CLA, exhibited a significantly (p<0.05) higher mRNA expression after 4 h, compared with controls. Enzyme activity peaked, and was significantly (p<0.05) higher after 6 h, compared with controls. With extension of the incubation time, TVA absorption into cells was significantly (p<0.05) higher with significantly (p<0.05) more conversion into cis-9, trans-11 CLA, compared with shorter incubation times. TVA incubated cells exhibited significantly (p<0.05) higher levels of arachidonic, eicosapentaenoic, and docosahexaenoic acids than controls. BEFS-PPARγ2 cells can be used as a model system and TVA incubation is a good approach for research into cis-9, trans-11 CLA-fortified beef production.

Effects of protein content and the inclusion of protein sources with different amino acid release dynamics on the nitrogen utilization of weaned piglets

Hu Nianzhi,Shen Zhiwen,Pan Li,Qin Guixin,Zhao Yuan,Bao Nan 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.2

Objective: We aimed to investigate the effect of the differing amino acid (AA) release dynamics of two protein sources on the growth performance, nitrogen deposition, plasma biochemical parameters, and muscle synthesis and degradation of piglets when included in their diets at normal and low concentrations. Methods: Forty-eight piglets (Duroc×Landrace×Large White) with initial body weight of 7.45±0.58 kg were assigned to six groups and fed one of 6 diets. The 6 dietary treatments were arranged by 3×2 factorial with 3 protein sources and 2 dietary protein levels. They are NCAS (a normal protein content with casein), NBlend (a normal protein content with blend of casein and corn gluten meal), NCGM (a normal protein content with corn gluten meal), LCAS (a low protein content with casein), LBlend (a low protein content with blend of casein and corn gluten meal), LCGM (a low protein content with corn gluten meal). The release dynamics of AA in these diets were determined by in vitro digestion. The digestibility, utilization and biological value of nitrogen in piglets were determined by micro Kjeldahl method. Plasma insulin was measured by enzyme-linked immunosorbent assay kits. The protein expression of mediators of muscle synthesis and degradation was determined by western blotting. Results: Although the consumption of a low-protein diet supplemented with crystalline AA was associated with greater nitrogen digestion and utilization (p<0.05), the final body weight, growth performance, nitrogen deposition, and phosphorylation of ribosomal protein S6 kinase 1 and eIF4E binding protein 1 in the muscle of pigs in the low-protein diet-fed groups were lower than those of the normal-protein diet-fed groups (p<0.05) because of the absence of non-essential AA. Because of the more balanced release of AA, the casein (CAS) and Blend-fed groups showed superior growth performance, final body weight and nitrogen deposition, and lower expression of muscle ring finger 1 and muscle atrophy F-box than the CGM-fed groups (p<0.05). Conclusion: We conclude that the balanced release of AA from CAS containing diets and mixed diets could reduce muscle degradation, favor nitrogen retention, % intake and improve growth performance in pigs consuming either a normal- or low-protein diet. Objective: We aimed to investigate the effect of the differing amino acid (AA) release dynamics of two protein sources on the growth performance, nitrogen deposition, plasma biochemical parameters, and muscle synthesis and degradation of piglets when included in their diets at normal and low concentrations.Methods: Forty-eight piglets (Duroc×Landrace×Large White) with initial body weight of 7.45±0.58 kg were assigned to six groups and fed one of 6 diets. The 6 dietary treatments were arranged by 3×2 factorial with 3 protein sources and 2 dietary protein levels. They are NCAS (a normal protein content with casein), NBlend (a normal protein content with blend of casein and corn gluten meal), NCGM (a normal protein content with corn gluten meal), LCAS (a low protein content with casein), LBlend (a low protein content with blend of casein and corn gluten meal), LCGM (a low protein content with corn gluten meal). The release dynamics of AA in these diets were determined by in vitro digestion. The digestibility, utilization and biological value of nitrogen in piglets were determined by micro Kjeldahl method. Plasma insulin was measured by enzyme-linked immunosorbent assay kits. The protein expression of mediators of muscle synthesis and degradation was determined by western blotting.Results: Although the consumption of a low-protein diet supplemented with crystalline AA was associated with greater nitrogen digestion and utilization (p<0.05), the final body weight, growth performance, nitrogen deposition, and phosphorylation of ribosomal protein S6 kinase 1 and eIF4E binding protein 1 in the muscle of pigs in the low-protein diet-fed groups were lower than those of the normal-protein diet-fed groups (p<0.05) because of the absence of non-essential AA. Because of the more balanced release of AA, the casein (CAS) and Blend-fed groups showed superior growth performance, final body weight and nitrogen deposition, and lower expression of muscle ring finger 1 and muscle atrophy F-box than the CGM-fed groups (p<0.05).Conclusion: We conclude that the balanced release of AA from CAS containing diets and mixed diets could reduce muscle degradation, favor nitrogen retention, % intake and improve growth performance in pigs consuming either a normal- or low-protein diet.

The Integrins Involved in Soybean Agglutinin-Induced Cell Cycle Alterations in IPEC-J2

Pan, Li,Zhao, Yuan,Yuan, Zhijie,Farouk, Mohammed Hamdy,Zhang, Shiyao,Bao, Nan,Qin, Guixin Korean Society for Molecular and Cellular Biology 2017 Molecules and cells Vol.40 No.2

Soybean agglutinin (SBA) is an anti-nutritional factor of soybean, affecting cell proliferation and inducing cytotoxicity. Integrins are transmembrane receptors, mediating a variety of cell biological processes. This research aims to study the effects of SBA on cell proliferation and cell cycle progression of the intestinal epithelial cell line from piglets (IPEC-J2), to identify the integrin subunits especially expressed in IPEC-J2s, and to analyze the functions of these integrins on IPEC-J2 cell cycle progression and SBA-induced IPEC-J2 cell cycle alteration. The results showed that SBA lowered cell proliferation rate as the cell cycle progression from G0/G1 to S phase (P < 0.05) was inhibited. Moreover, SBA lowered mRNA expression of cell cycle-related gene CDK4, Cyclin E and Cyclin D1 (P < 0.05). We successfully identified integrins ${\alpha}2$, ${\alpha}3$, ${\alpha}6$, ${\beta}1$, and ${\beta}4$ in IPEC-J2s. These five subunits were crucial to maintain normal cell proliferation and cell cycle progression in IPEC-J2s. Restrain of either these five subunits by their inhibitors, lowered cell proliferation rate, and arrested the cells at G0/G1 phase of cell cycle (P < 0.05). Further analysis indicated that integrin ${\alpha}2$, ${\alpha}6$, and ${\beta}1$ were involved in the blocking of G0/G1 phase induced by SBA. In conclusion, these results suggested that SBA lowered the IPEC-J2 cell proliferation rate through the perturbation of cell cycle progression. Furthermore, integrins were important for IPEC-J2 cell cycle progression, and they were involved in the process of SBA-induced cell cycle progression alteration, which provide a basis for further revealing SBA anti-proliferation and anti-nutritional mechanism.

The Integrins Involved in Soybean Agglutinin-Induced Cell Cycle Alterations in IPEC-J2

Li Pan,Yuan Zhao,Zhijie Yuan,Mohammed Hamdy Farouk,Shiyao Zhang,Nan Bao,GuiXin Qin 한국분자세포생물학회 2017 Molecules and cells Vol.40 No.2

Soybean agglutinin (SBA) is an anti-nutritional factor of soybean, affecting cell proliferation and inducing cytotoxicity. Integrins are transmembrane receptors, mediating a variety of cell biological processes. This research aims to study the effects of SBA on cell proliferation and cell cycle progression of the intestinal epithelial cell line from piglets (IPEC-J2), to identify the integrin subunits especially expressed in IPEC-J2s, and to analyze the functions of these integrins on IPEC-J2 cell cycle progression and SBA-induced IPEC-J2 cell cycle alteration. The results showed that SBA lowered cell proliferation rate as the cell cycle progression from G0/G1 to S phase (P < 0.05) was inhibited. Moreover, SBA lowered mRNA expression of cell cycle-related gene CDK4, Cyclin E and Cyclin D1 (P < 0.05). We successfully identified integrins 2, 3, 6, 1, and 4 in IPEC-J2s. These five subunits were crucial to maintain normal cell proliferation and cell cycle progression in IPEC-J2s. Restrain of either these five subunits by their inhibitors, lowered cell proliferation rate, and arrested the cells at G0/G1 phase of cell cycle (P < 0.05). Further analysis indicated that integrin 2, 6, and 1 were involved in the blocking of G0/G1 phase induced by SBA. In conclusion, these results suggested that SBA lowered the IPEC-J2 cell proliferation rate through the perturbation of cell cycle progression. Furthermore, integrins were important for IPEC-J2 cell cycle progression, and they were involved in the process of SBA-induced cell cycle progression alteration, which provide a basis for further revealing SBA anti-proliferation and anti-nutritional mechanism.