High Protein Research Articles

Exploring the unfolding pathways of protein families using Elastic Network Model

We explore how a protein’s native structure determines its unfolding process. We examine how the local structural features, like shear, and the global structural properties, like the number of soft modes, change during unfolding. Simulations are performed using a Gaussian Network Model (GNM) with bond breaking for both thermal and force-induced unfolding scenarios. We find that unfolding starts in areas of high shear in the native structure and progressively spreads to the low shear regions. Interestingly, analysis of single domain protein families (Chymotrypsin inhibitor and Barnase) reveal that proteins with distinct unfolding pathways exhibit divergent behavior of the number of soft modes during unfolding. This suggests that the number of soft modes might be a valuable tool for understanding thermal unfolding pathways. Additionally, we found a strong link between a protein’s overall structural similarity (TM-score) and its unfolding pathways, highlighting the importance of the native structure in determining how a protein unfolds.

Clinical and pathological features of cerebrospinal meningitis caused by Pantoea agglomerans : a case report

BackgroundPantoea agglomerans (P. agglomerans) is a gram-negative bacterium that is commonly isolated from plant surfaces, seeds, and the environment. As an opportunistic pathogen, it can cause blood, urinary and soft tissue infections in immunocompromised patients. In central nervous system, P. agglomerans infection has been report in children and immune-compromised patients, however, infection by such bacterium in nontraumatized immune competent adults has not been reported. Here, we report a case of P. agglomerans cerebrospinal meningitis accompanied by positive anti-myeloperoxidase (MPO) antibody in a 49-year-old female who has a history of black fungus planting.Case presentationThe patient manifested with repeated fever, headache, generalized muscle pain, and neurological defects. Cerebrospinal fluid (CSF) tests revealed a moderately elevated number of polymorphonuclear leukocytes (50–193 × 106/L), low glucose levels (0.54–2.44 mmo1/L), and extremely high protein content (2.42–25.42 g/L). Blood tests showed positive anti-myeloperoxidase antibodies lasting for 1.5 year before turning negative. Spine MRI showed thickening and enhancement of the whole spinal meninges. CSF metagenomic next-generation sequencing (mNGS) revealed 75,189 specific DNA reads of P. agglomerans. The patient underwent spinal laminectomy due to meningeal adhesions. Pathological results revealed fibrous tissue proliferation, inflammatory infiltration with focal necrosis and calcification in the dura mater. The patient was successfully treated with sufficient antibiotics at 1-year follow-up.ConclusionsPeople should be alert to CNS infections caused by P. agglomerans which presented with relatively mild clinical symptoms at onset, especially for those who contucts relevant agricultural and forestry work. The CSF characterization of P. agglomerans meningitis is elevated multiple nuclei white blood cells, significantly reduced glucose content, and markedly increased protein level which may be related to the secondary spinal membrane adhesions.

The HCoV-HKU1 N-Terminal Domain Binds a Wide Range of 9-O-Acetylated Sialic Acids Presented on Different Glycan Cores.

Coronaviruses (CoVs) recognize a wide array of protein and glycan receptors by using the S1 subunit of the spike (S) glycoprotein. The S1 subunit contains two functional domains: the N-terminal domain (S1-NTD) and the C-terminal domain (S1-CTD). The S1-NTD of SARS-CoV-2, MERS-CoV, and HCoV-HKU1 possesses an evolutionarily conserved glycan binding cleft that facilitates weak interactions with sialic acids on cell surfaces. HCoV-HKU1 employs 9-O-acetylated α2-8-linked disialylated structures for initial binding, followed by TMPRSS2 receptor binding and virus-cell fusion. Here, we demonstrate that the HCoV-HKU1 NTD has a broader receptor binding repertoire than previously recognized. We presented HCoV-HKU1 NTD Fc chimeras on a nanoparticle system to mimic the densely decorated surface of HCoV-HKU1. These proteins were expressed by HEK293S GnTI- cells, generating species carrying Man-5 structures, often observed near the receptor binding site of CoVs. This multivalent presentation of high mannose-containing NTD proteins revealed a much broader receptor binding profile compared to that of its fully glycosylated counterpart. Using glycan microarrays, we observed that 9-O-acetylated α2-3-linked sialylated LacNAc structures are also bound, comparable to OC43 NTD, suggesting an evolutionarily conserved glycan-binding modality. Further characterization of receptor specificity indicated promiscuous binding toward 9-O-acetylated sialoglycans, independent of the glycan core (glycolipids, N- or O-glycans). We demonstrate that HCoV-HKU1 may employ additional sialoglycan receptors to trigger conformational changes in the spike glycoprotein to expose the S1-CTD for proteinaceous receptor binding.

Bidirectional regulation of motor circuits using magnetogenetic gene therapy.

Here, we report a magnetogenetic system, based on a single anti-ferritin nanobody-TRPV1 receptor fusion protein, which regulated neuronal activity when exposed to magnetic fields. Adeno-associated virus (AAV)-mediated delivery of a floxed nanobody-TRPV1 into the striatum of adenosine-2a receptor-Cre drivers resulted in motor freezing when placed in a magnetic resonance imaging machine or adjacent to a transcranial magnetic stimulation device. Functional imaging and fiber photometry confirmed activation in response to magnetic fields. Expression of the same construct in the striatum of wild-type mice along with a second injection of an AAVretro expressing Cre into the globus pallidus led to similar circuit specificity and motor responses. Last, a mutation was generated to gate chloride and inhibit neuronal activity. Expression of this variant in the subthalamic nucleus in PitX2-Cre parkinsonian mice resulted in reduced c-fos expression and motor rotational behavior. These data demonstrate that magnetogenetic constructs can bidirectionally regulate activity of specific neuronal circuits noninvasively in vivo using clinically available devices.

Assessment of the Nutritional Value and Antioxidant Properties of Plant-Based Yogurt from Chickpeas

Plant-based yogurts are becoming more and more popular. These are vegan products for people with food allergies or intolerances, athletes, and ordinary consumers. The use of chickpea “milk” allows one to obtain a plant-based yogurt with a high protein content, dietary fiber and antioxidant potential. This study assessed the content of polyphenols, selected nutrients, and antioxidant properties in chickpea yogurt. The vegetable chickpea yogurt was rich in protein (4.34–7.90 g/100 g) and dietary fiber (2–4%). It was also characterized by a high antioxidant activity (DPPH = 2.61 to 4.32 μmol TE/g, FRAP = 3.11 to 48.33 μmol TE/g). The use of 3-day soaking and inoculation with Vegurt or a kefir bacterial inoculum allowed us to obtain a high protein content. The addition of honey increased the polyphenol content and antioxidant potential of the plant-based yogurt (139–148 GAE mg/100 g). This research will be used in future research into optimizing the conditions for obtaining plant-based yogurts with chickpeas. Further research should include models for testing health-promoting properties.

Grain Lysine enrichment and improved stress tolerance in rice through protein engineering.

Amino acids are a major source of nourishment for people living in regions where rice is a staple food. However, rice grain is deficient in essential amino acids, such as lysine. The activity of dihydrodipicolinate synthase (DHDPS) enzyme is crucial for lysine production in higher plants, but it is highly regulated through a feedback inhibition by its end product lysine, leading to its limited activity in the grain and resulting in low lysine accumulation. We identified lysine binding sites in the DHDPS enzyme and introduced key mutations to make it lysine feedback insensitive. Using in vivo analysis and functional complementation assays, we confirmed that protein engineering of the DHDPS renders it insensitive to lysine. Expression of mutated DHDPS resulted in 29 % higher lysine and 15 % higher protein accumulation in rice grains than the wild type. Importantly, the lysine content in transgenic grains was maintained in cooked rice. Further, the transgenic plants exhibited enhanced stress tolerance along with better antioxidant levels, improved photosynthesis, and higher grain yield compared to wild type plants. We have shown for the first time in rice that protein engineering of DHDPS can lead to accumulation of lysine in grains and impart abiotic stress tolerance. This approach could improve health in regions with nutrient deficiencies and environmental stressors that challenge food production and human health.

Protection efficacy and immunogenicity of Clostridium chauvoei proteins as a subunit blackleg vaccine or an adjuvant for Clostridium perfringens epsilon toxoid

Potential application of Clostridium chauvoei proteins was studied as a subunit blackleg vaccine or a biological adjuvant for Clostridium perfringens epsilon toxoid vaccine. Extracellular and cell surface proteins were extracted from C. chauvoei culture, and their protective efficacy was evaluated by potency test in guinea pigs. In order to investigate the effect of cell surface proteins on C. perfringens epsilon toxoid immunogenicity, rabbits were inoculated subcutaneously twice with: C. perfringens type D toxoid supernatant + 200 μg C. chauvoei cell surface proteins (PR-200), toxoid supernatant + 400 μg cell surface proteins (PR-400), inactivated C. perfringens type D vaccine (Vac), toxoid supernatant (Tox), or PBS. Isolation of cell surface proteins yielded about 2.5 mg/L culture protein with a sharp band at 43 kDa probably corresponding to flagellin. Potency test demonstrated the protection ability of both cellular and extracellular proteins of C. chauvoei. ELISA showed that the highest antibody titers against epsilon toxoid belonged to PR-400 and Vac groups. The effect of days post immunization on antibody response was not significant. No significant difference was observed between PR-400 and Vac, as well as PR-200 and Tox groups. Clostridium chauvoei cell surface proteins may have the potential for application as a blackleg disease vaccine and an adjuvant for clostridial toxoids.

Effect of orange-fleshed sweet potato (Ipomoea batatas)-Bambara groundnut (Vigna subterranea) composite flour on quality properties of pasta.

Non-wheat flours are gaining attention as substitutes for wheat flour, offering the potential to optimize local resource utilization and alleviate the demand for wheat. The study investigates the use of non-wheat flours, particularly a blend of orange-fleshed sweet potato (OFSP) (Ipomoea batatas) and Bambara groundnut (BG) (Vigna subterranean), as a partial replacement for wheat flour in pasta production. The aim is to improve the utilization of local resources, reduce the reliance on wheat, and enhance the nutritional quality of pasta. The production of OFSP and BG flour took place at Agricultural Research Council Roodeplaat Campus. The data were analyzed using analysis of variance, and significant means were separated using the Duncan multiple range test. The research found that pasta made from composite flour significantly influenced its composition and cooking characteristics when compared to 100% wheat pasta. The most nutritionally enriched pasta was achieved with a blend of 50% wheat, 25% OFSP, and 25% BG, featuring higher protein, ash, and fiber content. Consumers preferred pasta made from a composite flour of 70% wheat, 15% OFSP, and 15% BG. This research suggests the potential for producing pasta using OFSP and BG composite flour as a viable option. PRACTICAL APPLICATION: The practical application of the research on orange-fleshed sweet potatoes-Bambara groundnut-based pasta has the potential to improve nutrition, stimulate local economies, enhance agricultural sustainability, and promote food security in regions where vitamin A deficiency is a concern and wheat importation is high.

Nutritional properties of pilot-scale manufactured single-cell proteins from a Corynebacterium glutamicum

ABSTRACT Single-cell proteins (SCPs) derived from microorganisms are sustainable and standard-manufacturable protein sources. Corynebacterium glutamicum is one of the prospective bacteria for SCP production. To evaluate nutritional properties of C. glutamicum-SCP, pilot-scale fermentation (3,000 L) was performed under standard conditions, resulting in 23 kg of SCP in dry weight. This C. glutamicum-SCP had high protein and low-fat contents (22.4% carbohydrates, 60.9% crude protein, and 3.3% crude fat). Its fatty acid profile comprised 0.25% saturated fatty acids, 0.16% unsaturated fatty acids, no trans fatty acids, and no cholesterol. Its total iron content was 9.78 mg/100 g, of which approximately 14.8% was heme iron (1.45 mg/100 g). The Digestible Indispensable Amino Acid Score (DIAAS) of C. glutamicum-SCP was 102, higher than that of soy protein isolate (90), pea protein concentrate (82), house cricket (89), or yellow mealworm (64). In conclusion, C. glutamicum-SCP can be a promising alternative protein source to replace red meat.

Synergistic effects of alkaline and heat treatments on structural and functional properties of mung bean protein isolate: improving physicochemical stability of plant‐based emulsions

SummaryPlant‐based meat alternatives often require fat replacers to mimic the texture of traditional products. This study aimed to develop plant‐based emulsion gels using mung bean protein isolate (MBPI) as a potential fat substitute. However, creating these gels via heat setting requires a high protein concentration, which demands modification of the MBPI structure to enhance emulsifying properties. This study investigated synergistic effects of alkaline treatment (0.3 or 3.5% Na2CO3) and heat treatments (40 or 70 °C) on the functional properties of MBPI at high protein levels, for potential application as a plant‐based emulsion. The combined treatments reduced the zeta potential of protein suspensions from −9 to −19 mV and altered the protein conformation to form smaller particles (from 426 to 166 μm) with increased β‐sheet content. These treatments improved dispersibility of 8% MBPI suspension (58 to 86%), emulsifying activity index (6.34–10.89 m2 g−1), and stability coefficient (43 to 96%). Notably, MBPI samples treated with 0.3% Na2CO3 at 40 and 70 °C exhibited excellent emulsifying properties, forming stable monolayers at the oil–water interface, likely due to the increased surface activity of MBPI. Increasing protein concentration to 11% facilitated heat‐set gel formation; however, addition of 3.5%‐Na2CO3 induced premature gelation, limiting its application in emulsions. At 0.3%‐Na2CO3, increasing the protein content from 8% to 11% and the oil content from 10% to 30% further reduced emulsion droplet size, especially for MBPI treated with 0.3% Na2CO3 at 70 °C (MB‐0.3%‐70 °C) from 5.10 to 2.61 μm, likely due to decreased coalescence. This treatment yielded superior MBPI‐stabilised emulsion gels with enhanced penetration, fluid retention, and stability by possibly reducing protein aggregation. These findings demonstrate the potential of MBPI modified by combined addition of 0.3% Na2CO3 and heat treatment, particularly MB‐0.3%‐70 °C, as a promising ingredient for producing plant‐based emulsions.

Structural features of skeletal muscle titin aggregates

Titin is a multidomain protein of striated and smooth muscles of vertebrates. The protein consists of repeating immunoglobulin-like (Ig) and fibronectin-like (FnIII) domains, which are β-sandwiches with a predominant β-structure, and also contains disordered regions. In this work, the methods of atomic force microscopy (AFM), X-ray diffraction and Fourier transform infrared spectroscopy were used to study the morphology and structure of aggregates of rabbit skeletal muscle titin obtained in two different solutions: 0.15 M glycine-KOH, pH 7.0 and 200 mM KCl, 10 mM imidazole, pH 7.0. According to AFM data, skeletal muscle titin formed amorphous aggregates of different morphology in the above two solutions. Amorphous aggregates of titin formed in a solution containing glycine consisted of much larger particles than aggregates of this protein formed in a solution containing KCl. The “KCl-aggregates” according to AFM data had the form of a “sponge”-like structure, while amorphous “glycine-aggregates” of titin formed “branching” structures. Spectrofluorometry revealed the ability of titin “glycine aggregates” to bind to the dye thioflavin T (TT), and X-ray diffraction revealed the presence of one of the elements of the amyloid cross β-structure, a reflection of ~4.6 Å, in these aggregates. These data indicate that the “glycine-aggregates” of titin are amyloid or amyloid-like. No similar structural features were found in titin “KCl-aggregates”; they also did not show the ability to bind to thioflavin T, indicating the non-amyloid nature of these titin aggregates. Fourier transform infrared spectroscopy revealed differences in the secondary structure of the two types of titin aggregates. The data obtained demonstrate the features of structural changes during the formation of intermolecular bonds between molecules of the giant titin protein during its aggregation. The data expand the understanding of the process of amyloid protein aggregation.

Characterization of systemic lupus erythematosus subtypes using cluster analysis: insights from lymphocyte subpopulations.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease, in which lymphocyte subsets were dysregulated. Incorporating lymphocyte subpopulations in cluster analysis offers a pathway for personalized and precise treatment, targeting specific abnormalities for more effective management. We conducted Gaussian clustering analysis on clinical data, serological data, urine test results, and lymphocyte subpopulations for SLE patients hospitalized from September 2008 to December 2019. A total of 1863 SLE patients from Xi'Jing Hospital were included. After excluding those without complete assessments, 1281 patients underwent flow cytometry for lymphocyte subsets. Five SLE clusters emerged: Cluster 1 with severe kidney involvement, high SLEDAI scores, and infection rates, often accompanied by rashes and edema; cluster 2 with high urinary protein but better renal function; cluster 3 with normal lymphocyte count and low positive antibodies; cluster 4 with frequent psychiatric symptoms and pulmonary arterial hypertension (PAH); and cluster 5 with fever, arthritis, hematologic involvement, and high IgG levels despite decreased B cells. All enrolled SLE patients were ultimately categorized into five distinct clinical phenotype groups, with lymphocyte testing being meaningful for patient stratification. This finding shed light on the intricate heterogeneity of SLE, emphasizing the need for a personalized medicine approach. Targeting specific abnormalities in lymphocyte subsets holds promise for more effective and precise management of SLE. Key Points • A comprehensive analysis of SLE patients, including lymphocyte subpopulations, revealed five distinct clusters with varying clinical characteristics, emphasizing the heterogeneity of the disease. • This heterogeneity underscores the need for a personalized medicine approach in SLE management, targeting specific lymphocyte subset abnormalities for more effective and precise treatment.

Mesoporous Silica Microparticle-Protein Complexes: Effects of Protein Size and Solvent Properties on Diffusion and Loading Efficiency

Oral administration of protein-based therapeutics is highly desirable due to lower cost, enhanced patient compliance, and convenience. However, the harsh pH environment of the gastrointestinal tract poses significant challenges. Silica-based carriers have emerged as potential candidates for the delivery of protein molecules, owing to their tuneable surface area and pore volume. We explored the use of a commercial mesoporous silica carrier, SYLOID, for the delivery of octreotide and bovine serum albumin (BSA) using a solvent evaporation method in three different solvents. The loading of proteins into SYLOID was driven by diffusion, as described by the Stokes-Einstein equation. Various parameters were investigated, such as protein size, diffusion, and solubility. Additionally, 3D fluorescence confocal imaging was employed to identify fluorescence intensity and protein diffusion within the carrier. Our results indicated that the loading process was influenced by the molecular size of the protein as octreotide exhibited a higher recovery rate (71%) compared to BSA (32%). The methanol-based loading of octreotide showed uniform diffusion into the silica carrier, whereas water and ethanol loading resulted in the drug being concentrated on the surface, as shown by confocal imaging, and further confirmed by scanning electron microscopy (SEM). Pore volume assessment supported these findings, showing that octreotide loaded with methanol had a low pore volume (1.2 cc/g). On the other hand, BSA loading was affected by its solubility in the three solvents, its tendency to aggregate, and its low solubility in ethanol and methanol, which resulted in dispersed particle sizes of 223 and 231 μm, respectively. This reduced diffusion into the carrier, as confirmed by fluorescence intensity and diffusivity values. This study underscores the importance of protein size, solvent properties, and diffusion characteristics when using porous carriers for protein delivery. Understanding these factors allows for the development of more effective oral protein-based therapeutics by enhancing loading efficiency. This, in turn, will lead to advances in targeted drug delivery and improved patient outcomes.

Reprogrammable 3D Shapes from 1D Metamaterial

AbstractThree billion years of evolution have produced a vast variety of protein molecules, whose functions are directly dependent on their ability to assume and maintain specific shapes. Proteins are defined by the sequence and chemical characteristics of their amino acids, which dictate their 3D shape and function, ranging from enzymatic activity to immune responses. Here, we explore a synthetic form of linear structure that can be bent in a programmable way into various specific 3D shapes inspired by the way functional proteins are defined using genetic codes. This synthetic structure is based on non‐circular multistable corrugated tubes, which can be fabricated at various length scales and cross‐sectional shapes, thus enabling the modification of their properties. Additionally, the cross‐section shape can be rewritten multiple times, allowing for the repair of structural damage and the rewriting of the properties of the structure's multi‐stability. A numerical model is used to describe the bending energy landscape of different cross‐sections. The proposed reprogrammable 3D shapes of a rewritable 1D metamaterial are promising candidates for futuristic robotic systems, complex deployable structures, catheter devices, and energy absorption and harvesting.

One-step nanoscale expansion microscopy reveals individual protein shapes.

The attainable resolution of fluorescence microscopy has reached the subnanometer range, but this technique still fails to image the morphology of single proteins or small molecular complexes. Here, we expand the specimens at least tenfold, label them with conventional fluorophores and image them with conventional light microscopes, acquiring videos in which we analyze fluorescence fluctuations. One-step nanoscale expansion (ONE) microscopy enables the visualization of the shapes of individual membrane and soluble proteins, achieving around 1-nm resolution. We show that conformational changes are readily observable, such as those undergone by the ~17-kDa protein calmodulin upon Ca2+ binding. ONE is also applied to clinical samples, analyzing the morphology of protein aggregates in cerebrospinal fluid from persons with Parkinson disease, potentially aiding disease diagnosis. This technology bridges the gap between high-resolution structural biology techniques and light microscopy, providing new avenues for discoveries in biology and medicine.

Proteomic Analysis of Human Serum Proteins Adsorbed onto Collagen Barrier Membranes

Collagen barrier membranes are frequently used in guided tissue and bone regeneration. The aim of this study was to analyze the signature of human serum proteins adsorbed onto collagen membranes using a novel protein extraction method combined with mass spectrometry. Native porcine-derived collagen membranes (Geistlich Bio-Gide®, Wolhusen, Switzerland) were exposed to pooled human serum in vitro and, after thorough washing, subjected to protein extraction either in conjunction with protein enrichment or via a conventional surfactant-based method. The extracted proteins were analyzed via liquid chromatography with tandem mass spectrometry. Bioinformatic analysis of global profiling, gene ontology, and functional enrichment of the identified proteins was performed. Overall, a total of 326 adsorbed serum proteins were identified. The enrichment and conventional methods yielded similar numbers of total (315 vs. 309), exclusive (17 vs. 11), and major bone-related proteins (18 vs. 14). Most of the adsorbed proteins (n = 298) were common to both extraction groups and included several growth factors, extracellular matrix (ECM) proteins, cell adhesion molecules, and angiogenesis mediators involved in bone regeneration. Functional analyses revealed significant enrichment of ECM, exosomes, immune response, and cell growth components. Key proteins [transforming growth factor-beta 1 (TGFβ1), insulin-like growth factor binding proteins (IGFBP-5, -6, -7)] were exclusively detected with the enrichment-based method. In summary, native collagen membranes exhibited a high protein adsorption capacity in vitro. While both extraction methods were effective, the enrichment-based method showed distinct advantages in detecting specific bone-related proteins. Therefore, the use of multiple extraction methods is advisable in studies investigating protein adsorption on biomaterials.

Insects as Sustainable Feed: Enhancing Animal Nutrition and Reducing Livestock Environmental Impression.

Insects are emerging as a promising alternative source in animal nutrition, offering high protein content and a low environmental impression compared to traditional feed sources. This abstract explores the potential role of insects in reducing the environmental impact of livestock production. Insects such as black soldier fly larvae, mealworms, and crickets are rich in essential nutrients, including proteins, amino acids, fatty acids and so on. They can be efficiently farmed on organic waste streams, contributing to resource efficiency and waste lessening. Additionally, insect farming needs a small quantity of water, less land, and emits fewer greenhouse gases than conventional animal feed production. Despite these benefits, several challenges must be addressed to realize their potential, including regulatory approval, consumer acceptance, production scalability, and ensuring consistent nutritional quality. By overcoming these challenges through research, innovation, and policy support, insects can be integrated into mainstream animal feed systems, significantly reducing the environmental impact of livestock farming and contributing to a more sustainable agricultural future.

Carrier-Guided Proteome Analysis in a High Protein Background: An Improved Approach to Host Cell Protein Identification.

Many shotgun proteomics experiments are negatively influenced by highly abundant proteins, such as those measuring residual host cell proteins (HCP) amidst highly abundant recombinant biotherapeutic or plasma proteins amidst albumin and immunoglobulins. While western blotting and ELISAs can reveal the presence of specific low abundance proteins from highly abundant background proteins, mass spectrometry approaches are required to define the low abundance protein composition in these scenarios. The challenge in detecting low abundance proteins in a high protein background by standard shotgun approaches is that spectra are often not triggered on their peptides in data dependent acquisition methods but rather on the highly abundant background peptides. Here, we use tandem mass tags (TMT) to introduce a carrier proteome approach to enhance the detection of proteins, such as from residual host cell proteomes amidst a highly abundant background. Using a mixture of bovine serum albumin (BSA) and E. coli as a mock high background/low abundance target protein formulation, we demonstrate proof-of-principle experiments allowing the improved detection of target proteins amidst a high protein background. While we observed significant coisolation interference, we mitigated it by using a spike-in interference detection TMT channel. Finally, we use the approach to identify 300 residual E. coli proteins from a protein A pulldown of a human IgG antibody, demonstrating that it may be applicable to analysis of HCPs in biotherapeutic protein formulations.

Amaranth: Multipurpose Agroindustrial Crop

Amaranthus cruentus L. (varieties: Juana, Aurelia, Elena) and Amaranthus viridis L. (variety: Callaloo) have long been utilized in food products for human consumption in Central and South America. However, there is limited information on the chemical composition of these species’ leaves and grains grown in Puerto Rico. This study aimed to fill this gap by evaluating the nutritional profile of these four amaranth varieties cultivated in Puerto Rico. A compositional analysis was conducted using official methods, focusing on lysine, protein, dietary fiber, and mineral content. The results showed high lysine content in both species. Significant differences (p < 0.05) were found in crude protein levels among the leaves, with Elena (23%) and Aurelia (21%) showing the highest values. While protein content among grains averaged 19%, there were no significant differences between varieties. The analysis of dietary fiber revealed significant differences (p < 0.05) in insoluble dietary fiber (IDF) and total dietary fiber (TDF) for the leaves and in IDF, soluble dietary fiber (SDF), and TDF for the grains. Additionally, calcium, magnesium, and phosphorus concentrations differed significantly (p < 0.05) in the leaves, while iron, potassium, and zinc showed no significant variation. Significant differences were found in the grains for calcium, magnesium, iron, and phosphorus. This research highlights the excellent nutritional value of amaranth leaves and grains grown in Puerto Rico, with Elena and Aurelia having exceptionally high protein content in their leaves.

Sorghum Prolamin Scaffolds-Based Hybrid Cultured Meat with Enriched Sensory Properties.

Cultured meat (CM) has been hailed as a sustainable future meat production technology that requires scaffolds to support cell growth. Plant proteins are the most promising raw materials for edible scaffolds but remain underutilized. In this study, kafirin, an abundant, readily available, and nonallergenic prolamin extracted from red sorghum, was explored to fabricate 3D porous sponge-like scaffolds via a simple template-leaching method. The scaffolds featured fully interconnected pores with a high porosity of approximately 84% and mechanical properties of 1.0-1.9 kPa. Porcine skeletal muscle cells (PSCs) and adipose-derived stem cells (ADSCs) could adhere, proliferate, and differentiate on protein scaffolds. Thereafter, a hybrid CM was produced by culturing porcine ADSCs on kafirin scaffolds for 12 days, integrating plant protein-based and cell-based alternatives. The anthocyanins found in red sorghum contributed to the hybrid CM with meat-like color and antioxidative benefits. Moreover, the hybrid CM prototype demonstrated promising potential in providing higher protein content (22.9%) and unique mouthfeel and appearance characteristics, highlighting the viability of sorghum prolamin in promoting CM production.