The structure-function relationships and techno-functions of ß-conglycinin.

ß-conglycinin (ß-CG) is a prominent storage protein belonging to the globulin family in soybean (Glycine max) seeds. Along with other soybean proteins, it serves as an important source of essential amino acids and high-quality nutrition. However, the digestibility and nutritional value of ß-CG are key factors affecting the nutritional profile of soy-based foods. The heterotrimeric, secondary, and quaternary structures of ß-CG, particularly the spatial arrangement of its α, α', and ß subunits, influence its functional properties. Considering these aspects, ß-CG emerges as a significant protein with diverse applications in the food and health sectors. Therefore, this review explores ß-CG's composition, structure, function, health implications, and industrial uses. Salient discussions are presented on its molecular structure, nutrition, digestibility, allergenicity, and techno-functions including emulsification, solubility, gelling, and structure-function complexities. Overall, the multifaceted potential of ß-CG in the healthcare sector and the food industry is evident.

The screening of α-glucosidase inhibitory peptides from ß-conglycinin and hypoglycemic mechanism in HepG2 cells and zebrafish larvae.

Inhibition of carbohydrate digestive enzymes is a key focus across diverse fields, given the prominence of α-glucosidase inhibitors as preferred oral hypoglycaemic drugs for diabetes treatment. ß-conglycinin is the most abundant functional protein in soy; however, it is unclear whether the peptides produced after its gastrointestinal digestion exhibit α-glucosidase inhibitory properties. Therefore, we examined the α-glucosidase inhibitory potential of soy peptides. Specifically, ß-conglycinin was subjected to simulated gastrointestinal digestion by enzymatically cleaving it into 95 peptides with gastric, pancreatic and chymotrypsin enzymes. Eight soybean peptides were selected based on their predicted activity; absorption, distribution, metabolism, excretion and toxicity score; and molecular docking analysis. The results indicated that hydrogen bonding and electrostatic interactions play important roles in inhibiting α-glucosidase, with the tripeptide SGR exhibiting the greatest inhibitory effect (IC50 = 10.57 µg/mL). In vitro studies revealed that SGR markedly improved glucose metabolism disorders in insulin-resistant HepG2 cells without affecting cell viability. Animal experiments revealed that SGR significantly improved blood glucose and decreased maltase activity in type 2 diabetic zebrafish larvae, but it did not result in the death of zebrafish larvae. Transcriptomic analysis revealed that SGR exerts its anti-diabetic and hypoglycaemic effects by attenuating the expression of several genes, including Slc2a1, Hsp70, Cpt2, Serpinf1, Sfrp2 and Ggt1a. These results suggest that SGR is a potential food-borne bioactive peptide for managing diabetes.

Combining ulinastatin with TIENAM improves the outcome of sepsis induced by cecal ligation and puncture in mice by reducing inflammation and regulating immune responses.

Despite the high mortality associated with sepsis, effective and targeted treatments remain scarce. The use of conventional antibiotics such as TIENAM (imipenem and cilastatin sodium for injection, TIE) is challenging because of the increasing bacterial resistance, which diminishes their efficacy and leads to adverse effects. Our previous studies demonstrated that ulinastatin (UTI) exerts a therapeutic impact on sepsis by reducing systemic inflammation and modulating immune responses. In this study, we examined the possibility of administering UTI and TIE after inducing sepsis in a mouse model using cecal ligation and puncture (CLP). We assessed the rates of survival, levels of inflammatory cytokines, the extent of tissue damage, populations of immune cells, microbiota in ascites, and important signaling pathways. The combination of UTI and TIE significantly improved survival rates and reduced inflammation and bacterial load in septic mice, indicating potent antimicrobial properties. Notably, the survival rates of UTI+TIE-treated mice increased from 10 % to 75 % within 168 h compared to those of mice that were subjected to CLP. The dual treatment successfully regulated the levels of inflammatory indicators (interleukin [IL]-6, IL-1ß, and tumor necrosis factor [TNF]-α) and immune cell numbers by reducing B cells, natural killer cells, and TNFR2+ Treg cells and increasing CD8+ T cells. Additionally, the combination of UTI and TIE alleviated tissue damage, reduced bacterial load in the peritoneal cavity, and suppressed the NF-κB signaling pathway. Our findings indicate that UTI and TIE combination therapy can significantly enhance sepsis outcomes by reducing inflammation and boosting the immune system. The results offer a promising therapeutic approach for future sepsis treatment.

Enhancement of hydrogen bonds between proteins and polyphenols through magnetic field treatment: Structure, interfacial properties, and emulsifying properties.

In food systems, proteins and polyphenols typically coexist in a non-covalent manner. However, the inherent rigid structure of proteins may hinder the binding sites of polyphenols, thereby limiting the strength of their interaction. In the study, magnetic field (MF) treatment was used to enhance non-covalent interactions between coconut globulin (CG) and tannic acid (TA) to improve protein flexibility, enhancing their functional properties without causing oxidation of polyphenols. Based on protein structure results, the interaction between CG and TA caused protein structure to unfold, exposing hydrophobic groups. Treatment with a MF, particularly at 3 mT, further promoted protein unfolding, as evidenced by a decrease in α-helix structure and an increase in coil random. These structural transformations led to the exposure of the internal binding site bound to TA and strengthening the CG-TA interaction (polyphenol binding degree increased from 62.3 to 68.2%). The characterization of molecular forces indicated that MF treatment strengthened hydrogen bonding-dominated non-covalent interactions between CG and TA, leading to improved molecular flexibility of the protein. Specifically, at a MF treatment at 3 mT, CG-TA colloidal particles with small size and high surface hydrophobicity exhibited optimal interfacial activity and wettability (as evidenced by a three-phase contact angle of 89.0°). Consequently, CG-TA-stabilized high internal phase Pickering emulsions (HIPPEs) with uniform droplets and dense gel networks at 3 mT. Furthermore, the utilization of HIPPEs in 3D printing resulted in consistent geometric shapes, uniform surface textures, and distinct printed layers, demonstrating superior printing stability. As a result, MF treatment at 3 mT was identified as the most favorable. This research provides novel insights into how proteins and polyphenols interact, thereby enabling natural proteins to be utilized in a variety of food applications.

Accounting for differences between serum and plasma: An indirect approach to derive reference intervals for total protein, albumin, and globulin.

BACKGROUND: Observable quantitative variations exist between plasma and serum in routine protein measurements, often not reflected in standard reference intervals. In this study, we describe an indirect approach for estimating a combined reference interval (RI) (i.e., serum and plasma), for commonly ordered protein measurands: total protein, albumin, and globulin. METHODS: We applied an indirect reference interval estimation for protein measurements in serum and plasma using data from July 2018 to February 2024. The data were divided into three Epochs based on a period of plasma separator tube shortage during the COVID-19 pandemic. Bootstrap resampling was used to calculate RIs and corresponding 95% confidence intervals for each month. RESULTS: Our results demonstrate notable changes in RI limits for total protein, albumin, and globulin between Epochs, reflecting the influence of changing sample matrix. A combined RI was identified for all components and verified using plasma and serum samples from 20 healthy individuals and retrospective analysis of flagging rates on our outpatient population using new and historical RIs. CONCLUSION: The study demonstrates notable differences in the RIs for total protein, albumin, and globulin when container type changes. In addition, the results demonstrate the effectiveness of big data analytics in deriving RIs and highlights the necessity of continuous RI assessment and adjustment based on the patient population and acceptable specimen types.

Effect of extraction method on the calcium binding capacity of faba bean globulin fractions at various pH.

Faba bean ingredients are rich in proteins and good sources of calcium (Ca), although containing phytic acid (PA) molecules. PA, a polyphosphate compound, can affect the bioavailability of minerals/proteins through complex formation. This study evaluates the impact of two extraction processes, Alkaline Extraction-IsoElectric Precipitation (AE-IEP) and Sequential Extraction (SE), on the ability of faba bean globulin systems to bind added calcium ions. Increasing concentrations of CaCl2 were introduced into 2.5% (w/v) protein dispersions at pHs 4.5, 5.5, 6.5, and 7.5, and free Ca monitored. Near the isoelectric point of globulin (pH âˆ¼ 4-5), Ca binding capacity was found to be low. At higher pHs, significant Ca chelation occurred, initially attributed to free PA binding sites, resulting in the formation of insoluble complexes and subsequent protein precipitation. The AE-IEP globulin fraction exhibited a higher Ca binding capacity than the SE globulin, attributed to its higher PA and lower initial Ca concentrations.

Interactions of different polyphenols with wheat germ albumin and globulin: Alterations in the conformation and emulsification properties of proteins.

In this study, chlorogenic acid (CA), piceatannol (PIC), epigallocatechin-3-gallate (EGCG) and ferulic acid (FA) was selected to explore the influence of polyphenol on the structural properties of wheat germ albumin (WGA) and wheat germ globulin (WGG). The emulsifying properties of the emulsions prepared by WGA-EGCG complex were also evaluated. The results indicated that all polyphenols could significantly enhance the antioxidant capacity of WGA and WGG. In particular, EGCG increased the ratio of random coil in WGA and WGG, resulting in protein unfolding and shifting from an order to disorder structure. In addition, lipid oxidation and protein oxidation of the soybean oil emulsion was significantly slowed down by WGA-EGCG. The stability of the emulsions under various environmental stress and the storage time was significantly improved by WGA-EGCG. These findings can provide a reference for expanding the application of wheat germ protein in food industry.

The potential of glycinin basic peptide derived from soybean as a promising candidate for the natural food additive and preservative: A review.

Glycinin basic peptide (GBP) is the basic polypeptide of soybean glycinin that is isolated using cheap and readily available raw materials (soybean meals). GBP can bear high-temperature processing and has good functional properties, such as emulsification and adhesion properties et al. GBP exhibits broad-spectrum antimicrobial activities against Gram-positive and Gram-negative bacteria as well as fungi. Beyond that, GBP shows enormous application potential to improve the quality and extend the shelf life of food products. This review will systematically provide information on the purification, physicochemical and functional properties of GBP. Moreover, the antimicrobial activities and multi-target antimicrobial mechanism of GBP as well as the applications of GBP in different food products are also reviewed and discussed in detail. This review aims to offer valuable insights for the applications of GBP in the food industry as a promising natural food additive and preservative.

Synergistic enhancement of anthocyanin stability and techno-functionality of colored wheat during the steamed bread processing by selectively hydrolyzed soy protein.

To improve the stability of anthocyanins and techno-functionality of purple and blue wheat, the selectively hydrolyzed soy protein (reduced glycinin, RG) and ß-conglycinin (7S) were prepared and their enhanced effects were comparatively investigated. The anthocyanins in purple wheat showed higher stability compared to that of the blue wheat during breadmaking. The cyanidin-3-O-glucoside and cyanidin-3-O-rutincoside in purple wheat and delphinidin-3-O-rutinoside and delphinidin-3-O-glucoside in blue wheat were better preserved by RG. Addition of RG and 7S enhanced the quality of steamed bread made from colored and common wheat, with RG exhibited a more prominent effect. RG and 7S suppressed the gelatinization of starch and improved the thermal stability. Both RG and 7S promoted the unfolding process of gluten proteins and facilitated the subsequent crosslinking of glutenins and gliadins by disulfide bonds. Polymerization of α- and γ-gliadin into glutenin were more evidently promoted by RG, which contributed to the improved steamed bread quality.

A Quantity-Dependent Nonlinear Model of Sodium Cromoglycate Suppression on Beta-Conglycinin Transport.

Understanding the transport mechanism is crucial for developing inhibitors that block allergen absorption and transport and prevent allergic reactions. However, the process of how beta-conglycinin, the primary allergen in soybeans, crosses the intestinal mucosal barrier remains unclear. The present study indicated that the transport of beta-conglycinin hydrolysates by IPEC-J2 monolayers occurred in a time- and quantity-dependent manner. The beta-conglycinin hydrolysates were absorbed into the cytoplasm of IPEC-J2 monolayers, while none were detected in the intercellular spaces. Furthermore, inhibitors such as methyl-beta-cyclodextrin (MßCD) and chlorpromazine (CPZ) significantly suppressed the absorption and transport of beta-conglycinin hydrolysates. Of particular interest, sodium cromoglycate (SCG) exhibited a quantity-dependent nonlinear suppression model on the absorption and transport of beta-conglycinin hydrolysates. In conclusion, beta-conglycinin crossed the IPEC-J2 monolayers through a transcellular pathway, involving both clathrin-mediated and caveolae-dependent endocytosis mechanisms. SCG suppressed the absorption and transport of beta-conglycinin hydrolysates by the IPEC-J2 monolayers by a quantity-dependent nonlinear model via clathrin-mediated and caveolae-dependent endocytosis. These findings provide promising targets for both the prevention and treatment of soybean allergies.

Generation of New ß-Conglycinin-Deficient Soybean Lines by Editing the lincRNA lincCG1 Using the CRISPR/Cas9 System.

Soybean ß-conglycinin is a major allergen that adversely affects the nutritional properties of soybean. Soybean deficient in ß-conglycinin is associated with low allergenicity and high nutritional value. Long intergenic noncoding RNAs (lincRNAs) regulate gene expression and are considered important regulators of essential biological processes. Despite increasing knowledge of the functions of lincRNAs, relatively little is known about the effects of lincRNAs on the accumulation of soybean ß-conglycinin. The current study presents the identification of a lincRNA lincCG1 that was mapped to the intergenic noncoding region of the ß-conglycinin α-subunit locus. The full-length lincCG1 sequence was cloned and found to regulate the expression of soybean seed storage protein (SSP) genes via both cis- and trans-acting regulatory mechanisms. Loss-of-function lincCG1 mutations generated using the clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) system led to the deficiency of the allergenic α'-, α-, and ß-subunits of soybean ß-conglycinin as well as higher content of proteins, sulfur-containing amino acids, and free arginine. The dominant null allele LincCG1, and consequently, the ß-conglycinin-deficient phenotype associated with the lincCG1-gene-edited line was stably inherited by the progenies in a Mendelian fashion. The dominant null allele LincCG1 may therefore be exploited for engineering/developing novel hypoallergenic soybean varieties. Furthermore, Cas9-free and ß-conglycinin-deficient homozygous mutant lines were obtained in the T1 generation. This study is the first to employ the CRISPR/Cas9 technology for editing a lincRNA gene associated with the soybean allergenic protein ß-conglycinin. Moreover, this study reveals that lincCG1 plays a crucial role in regulating the expression of the ß-conglycinin subunit gene cluster, besides highlighting the efficiency of employing the CRISPR/Cas9 system for modulating lincRNAs, and thereby regulating soybean seed components.

miRNA Expression Analysis of IPEC-J2 Cells Damaged by Soybean 7S Globulin Reveals ssc-miR-221-5p as the Factor Alleviating Cell Damage.

The most significant and sensitive antigen protein that causes diarrhea in weaned pigs is soybean 7S globulin. Therefore, identifying the primary target for minimizing intestinal damage brought on by soybean 7S globulin is crucial. MicroRNA (miRNA) is closely related to intestinal epithelium's homeostasis and integrity. However, the change of miRNAs' expression and the function of miRNAs in Soybean 7S globulin injured-IPEC-J2 cells are still unclear. In this study, the miRNAs' expression profile in soybean 7S globulin-treated IPEC-J2 cells was investigated. Fifteen miRNAs were expressed differently. The differentially expressed miRNA target genes are mainly concentrated in signal release, cell connectivity, transcriptional inhibition, and Hedgehog signaling pathway. Notably, we noticed that the most significantly decreased miRNA was ssc-miR-221-5p after soybean 7S globulin treatment. Therefore, we conducted a preliminary study on the mechanisms of ssc-miR-221-5p in soybean 7S globulin-injured IPEC-J2 cells. Our research indicated that ssc-miR-221-5p may inhibit ROS production to alleviate soybean 7S globulin-induced apoptosis and inflammation in IPEC-J2 cells, thus protecting the cellular mechanical barrier, increasing cell proliferation, and improving cell viability. This study provides a theoretical basis for the prevention and control of diarrhea of weaned piglets.

Insight into the interaction and binding mechanism of a natural nonnutritive sweetener mogroside V with soybean protein isolates based on multi-spectroscopic techniques and computational simulations.

As a natural low-calorie sweetener, Mogroside V (Mog-V) has gradually become one of the alternatives to sucrose with superior health attributes. However, Mog-V will bring unpleasant aftertastes when exceeding a threshold concentration. To investigate the possibility of soy protein isolates (SPIs), namely ß-conglycinin (7S), and glycinin (11S) as flavor-improving agents of Mog-V, the binding mechanism between Mog-V and SPIs was explored through multi-spectroscopy, particle size, zeta potential, and computational simulation. The results of the multi-spectroscopic experiments indicated that Mog-V enhanced the fluorescence of 7S/11S protein in a static mode. The binding affinity of 7S-Mog-V was greater compared with 11S-Mog-V. Particle size and zeta potential analysis revealed that the interaction could promote aggregation of 7S/11S protein with different stability. Furthermore, computational simulations further confirmed that Mog-V could interact with the 7S/11S protein in different ways. This research provides a theoretical foundation for the development and application of SPI to improve the flavor of Mog-V, opening a new avenue for further expanding the market demand for Mog-V.

Crystal structure of hetero hexameric 11S seed storage protein of hazelnut.

Edible plant seeds provide a relatively inexpensive source of protein and make up a large part of nutrients for humans. Plant seeds accumulate storage proteins during seed development. Seed storage proteins act as a reserve of nutrition for seed germination and seedling growth. However, seed storage proteins may be allergenic, and the prevalence of food allergy has increased rapidly in recent years. The 11S globulins account for a significant number of known major food allergens. They are of interest to the public and the agricultural industry because of food safety concerns and the need for crop enhancement. We sought to determine the crystal structure of Cor a 9, the 11 S storage protein of hazelnut and a food allergen. The structure was refined to 1.92 Å, and the R and Rfree for the refined structure are 17.6% and 22.5%, respectively. The structure of Cor a 9 showed a hetero hexamer of an 11S seed storage protein for the first time. The hexamer was two trimers associated back-to-back. Two long alpha helixes at the C-terminal end of the acidic domain of one of the Cor a 9 isoforms lay at the trimer-trimer interface's groove. These data provided much-needed information about the allergenicity of the 11S seed proteins. The information may also facilitate a better understanding of the folding and transportation of 11S seed storage proteins.

Localization of G1A1a Allergenic Domain Destroyed by Thermal Processing.

Glycinin is an important allergenic protein. A1a is the acidic chain of the G1 subunit in glycinin (G1A1a), and it has strong allergenicity. In this study, we used phage display technology to express the protein of G1A1a and its overlapping fragments and an indirect enzyme-linked immunosorbent assay (iELISA) to determine the antigenicity and allergenicity of the expressed protein. After three rounds of screening, it was determined that fragment A1a-2-B-I (151SLENQLDQMPRRFYLAGNQEQEFLKYQQEQG181) is the allergenic domain of G1A1a destroyed by thermal processing. In addition, three overlapping peptides were synthesized from fragments A1a-2-B-I, and a linear epitope was found in this domain through methods including dot blot and iELISA. Peptide 2 (157DQMPRRFYLANGNQE170) showed allergenicity, and after replacing it with alanine, it was found that amino acids D157, Q158, M159, and Y164 were the key amino acids that affected its antigenicity, while Q158, M159, R162, and N168 affected allergenicity.

Conformation-Activity Mechanism of Alcalase Hydrolysis for Reducing In Vitro Allergenicity of Instant Soy Milk Powder.

Effective reduction of the allergenicity of instant soy milk powder (ISMP) is practically valuable for expanding its applications. This study optimized the enzymolysis technology of ISMP using single-factor experiments and response surface methodology, combined serological analysis, cellular immunological models, bioinformatics tools, and multiple spectroscopy techniques to investigate the effects of alcalase hydrolysis on allergenicity, spatial conformation, and linear epitopes of ISMP. Under the optimal process, special IgE and IgG1 binding abilities and allergenic activity to induce cell degranulation of alcalase-hydrolyzed ISMP were reduced by (64.72 ± 1.76)%, (56.79 ± 3.72)%, and (73.3 ± 1.19)%, respectively (P < 0.05). Moreover, the spatial conformation of instant soy milk powder hydrolysates (ISMPH) changed, including decreased surface hydrophobicity, a weaker peak of amide II band, lower contents of α-helix and ß-sheet, and an enhanced content of random coil. Furthermore, the linear epitopes of major soy allergens, 9 from glycinin and 13 from ß-conglycinin, could be directionally disrupted by alcalase hydrolysis. Overall, the structure-activity mechanism of alcalase hydrolysis to reduce ISMP allergenicity in vitro was preliminarily clarified. It provided a new research direction for the breakthrough in the desensitization of ISMP and a theoretical basis for revealing the potential mechanism of alcalase enzymolysis to reduce the allergenicity of ISMP.

Characterization of structural and functional properties of soybean 11S globulin during renaturation after denaturation induced by changes in pH.

BACKGROUND: This study explored the denaturation of 11S globulin, a protein known for its diverse functional properties in soy protein applications, at pH 3.0 and pH 10.0, followed by a gradual return to pH 7.0 to facilitate renaturation. It investigated the structural and functional changes during renaturation induced by a change in pH, revealing the stabilization mechanism of 11S globulin. RESULTS: The findings revealed that during pH adjustment to neutral, the denatured soybean 11S globulin - resulting from alkaline (pH 10.0) or acidic (pH 3.0) treatments - experienced a refolding of its extended tertiary structure to varying extents. The particle size and the proportions of α-helix and ß-sheet in the secondary structure aligned progressively with those of the natural-state protein. However, for the alkali-denatured 11S, the ß-sheet content decreased upon adjustment to neutral, whereas an increase was observed for the acid-denatured 11S. In terms of functional properties, after alkaline denaturation, the foaming capacity (FC) and emulsifying activity index (EAI) of 11S increased by 1.4 and 1.2 times, respectively, in comparison with its native state. The solubility, foamability, and emulsifiability of the alkali-denatured 11S gradually diminished during renaturation but remained superior to those of the native state. Conversely, these properties showed an initial decline, followed by an increase during renaturation triggered by pH neutralization. CONCLUSIONS: This research contributes to the enhancement of protein functionality, offering a theoretical foundation for the development of functional soy protein products and expanding their potential applications. © 2024 Society of Chemical Industry.

Liposomes decorated with ß-conglycinin and glycinin: Construction, structure and in vitro digestive stability.

Liposomes were modified with different proportions of ß-conglycinin (7S) and glycinin (11S) to form Lip-7S and Lip-11S. The morphology, interaction and in vitro simulated digestion of liposomes were studied. The particle size of Lip-7S was smaller than that of Lip-11S. When the values of Lip-7S and Lip-11S were 1:1 and 1:0.75, respectively, the ζ-potential had the maximum absolute value and the dispersion of the system was good. The results of multispectral analysis showed that hydrogen-bond and hydrophobic interaction dominated protein-modified liposomes, the protein structure adsorbed on the surface of liposomes changed, the content of α-helix decreased, and the structure of protein-modified liposomes became denser. The surface hydrophobicity and micropolarity of liposomes decreased with the increase of protein ratio, and tended to be stable after Lip-7S (1:1) and Lip-11S (1:0.75). Differential scanning calorimetry showed that Lip-7S had higher phase transition temperature (≥170.5 °C) and better rigid structure. During simulated digestion, Lip-7S (22.5 %) released less Morin than Lip (40.6 %) and Lip-11S (26.2 %), and effectively delayed the release of FFAs. The environmental stability of liposomes was effectively improved by protein modification, and 7S had better modification effect than 11S. This provides a theoretical basis for 7S and 11S modified liposomes, and also provides a data reference for searching for new materials for stabilization of liposomes.

Non-linear relationship between preoperative albumin-globulin ratio and postoperative pneumonia in patients with hip fracture.

BACKGROUND AND OBJECTIVE: Postoperative pneumonia (POP) is the leading cause of death among patients with hip fractures. Simple and cost-effective markers can be used to assess the risk of these patients. This study aims to investigate the association between POP and preoperative albumin-globulin ratio (AGR) in patients with hip fractures. METHODS: A retrospective analysis was conducted on data from 1417 hip fracture patients admitted to the Department of Orthopaedics at the hospital. Generalized additive and logistic regression models were used to determine both linear and non-linear associations between preoperative AGR and POP. A two-piece regression model was employed to determine the threshold effect. RESULTS: The study included 1417 participants, with a mean age of 77.57 (8.53) years and 26.96% (382/1417) male patients. The prevalence of POP was 6.21%. Following full covariate adjustment, each unit increase in AGR was associated with a 79% reduction in the incidence of POP (OR, 0.23; 95% CI: 0.08-0.63; P = 0.0046). The inflection point was found to be 1.33 using a two-piecewise regression model. For each unit increase in AGR on the left side of the inflection point, the incidence of POP decreased by 93% (OR, 0.07; 95%CI: 0.02-0.34; P = 0.0010). However, there was no statistically significant correlation on the right side of the inflection point (OR, 0.84; 95% CI: 0.17-4.10; P = 0.8287). CONCLUSION: There exists a non-linear association between preoperative AGR and the incidence of POP in elderly hip fracture patients. When AGR is less than 1.33, the incidence of POP is negatively correlated with AGR. However, there is no correlation when AGR is greater than 1.33.

Homologous Overexpression of Tyrosinase in Trichoderma reesei and Its Application in Glycinin Cross-Linking.

Tyrosinase is capable of oxidizing tyrosine residues in proteins, leading to intermolecular protein cross-linking, which could modify the protein network of food and improve the texture of food. To obtain the recombinant tyrosinase with microbial cell factory instead of isolation tyrosinase from the mushroom Agaricus bisporus, a TYR expression cassette was constructed in this study. The expression cassette was electroporated into Trichoderma reesei Rut-C30 and integrated into its genome, resulting in a recombinant strain C30-TYR. After induction with microcrystalline cellulose for 7 days, recombinant tyrosinase could be successfully expressed and secreted by C30-TYR, corresponding to approximately 2.16 g/L tyrosinase in shake-flask cultures. The recombinant TYR was purified by ammonium sulfate precipitation and gel filtration, and the biological activity of purified TYR was 45.6 U/mL. The purified TYR could catalyze the cross-linking of glycinin, and the emulsion stability index of TYR-treated glycinin emulsion was increased by 30.6% compared with the untreated one. The cross-linking of soy glycinin by TYR resulted in altered properties of oil-in-water emulsions compared to emulsions stabilized by native glycinin. Therefore, cross-linking with this recombinant tyrosinase is a feasible approach to improve the properties of protein-stabilized emulsions and gels.