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Inoue Y, Tasaki M, Masuda T, Misumi Y, Nomura T, Ando Y, Ueda M. α-Enolase reduces cerebrovascular Aβ deposits by protecting Aβ amyloid formation. Cell Mol Life Sci 2022; 79:462. [PMID: 35916996 PMCID: PMC11072596 DOI: 10.1007/s00018-022-04493-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 06/29/2022] [Accepted: 07/17/2022] [Indexed: 11/03/2022]
Abstract
Cerebral amyloid angiopathy (CAA) is characterized by cerebrovascular amyloid β (Aβ) deposits and causes dementia and cerebral hemorrhage. Although α-enolase (ENO1) was shown to possess multifunctional roles, its exact functions in CAA pathogenesis have not been determined. In this study, we focused on ENO1, a well-known glycolytic enzyme, which was previously identified via a proteomic approach as an upregulated protein in brain samples from patients with Alzheimer's disease (AD). We utilized the thioflavin T fluorescence assay and transmission electron microscopy to monitor the effects of ENO1 on amyloid formation by Aβ peptides. We also cultured murine primary cerebrovascular smooth muscle cells to determine the effects of ENO1 on Aβ cytotoxicity. To investigate the effects of ENO1 in vivo, we infused ENO1 or a vehicle control into the brains of APP23 mice, a transgenic model of AD/CAA, using a continuous infusion system, followed by a cognitive test and pathological and biochemical analyses. We found that novel functions of ENO1 included interacting with Aβ and inhibiting its fibril formation, disrupting Aβ fibrils, and weakening the cytotoxic effects of these fibrils via proteolytic degradation of Aβ peptide. We also demonstrated that infusion of ENO1 into APP23 mouse brains reduced cerebrovascular Aβ deposits and improved cognitive impairment. In addition, we found that enzymatically inactivated ENO1 failed to inhibit Aβ fibril formation and fibril disruption. The proteolytic activity of ENO1 may thus underlie the enzyme's cytoprotective effect and clearance of Aβ from the brain, and ENO1 may be a therapeutic target in CAA.
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Affiliation(s)
- Yasuteru Inoue
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Chuo-ku, Honjo, Kumamoto, Kumamoto, 860-8556, Japan.
| | - Masayoshi Tasaki
- Department of Biomedical Laboratory Sciences, Graduate School of Health Sciences, Kumamoto University, Kumamoto, Japan
| | - Teruaki Masuda
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Chuo-ku, Honjo, Kumamoto, Kumamoto, 860-8556, Japan
| | - Yohei Misumi
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Chuo-ku, Honjo, Kumamoto, Kumamoto, 860-8556, Japan
| | - Toshiya Nomura
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Chuo-ku, Honjo, Kumamoto, Kumamoto, 860-8556, Japan
| | - Yukio Ando
- Department of Amyloidosis Research, Nagasaki International University, Sasebo, Japan
| | - Mitsuharu Ueda
- Department of Neurology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Chuo-ku, Honjo, Kumamoto, Kumamoto, 860-8556, Japan
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Tan Y, Chang SK. Protein extraction pH and cross-linking affect physicochemical and textural properties of protein gels made from channel catfish by-products. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2021; 101:4799-4807. [PMID: 33502763 DOI: 10.1002/jsfa.11126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 12/06/2020] [Accepted: 01/27/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Channel catfish farming is very important aquaculture industry in the southern states of the USA. However, huge amounts of by-products are generated from catfish fillet-processing. The by-products (mostly heads and bone frames) are excellent sources of proteins. Currently, catfish by-product has little value, and is regarded as a 'waste', which if not utilized properly could cause serious environmental pollution. Therefore, to find a way to utilize those by-products is critical for the economy of aquaculture. METHOD Protein isolates were extracted from the mixture of catfish by-products (heads and frames) under different alkaline conditions (pH 7.5-11) and made into protein gels. Secondary structures of extracted protein isolates were studied. Microbial transglutaminase (MTGase, 0-4 U g-1 proteins) was incorporated to improve gel structure. Gelling, physicochemical, textural and thermal properties of protein gels treated with/without MTGase were investigated. Protein pattern changes of MTGase-treated protein gels were studied and the microstructure of the protein gels was analyzed. RESULTS Alpha-helicity of protein isolates made at pH 11 was 21.5% lower than that extracted at pH 8.5. Storage modulus (G') of protein gel decreased with increasing extraction pH (pH > 9) of the corresponding protein isolate. MTGase treatment exhibited significant effects on denaturation temperature and enthalpy of protein gels. Excessive MTGase (>2 U g-1 ) could weaken the gel structure. CONCLUSION Protein isolates can be extracted from catfish by-products and made into protein gels, which are a value-added product. © 2021 Society of Chemical Industry.
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Affiliation(s)
- Yuqing Tan
- Beijing Laboratory for Food Quality and Safety, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
- Department of Food Science, Nutrition and Health Promotion, Mississippi State University, Starkville, MS, USA
| | - Sam Kc Chang
- Department of Food Science, Nutrition and Health Promotion, Mississippi State University, Starkville, MS, USA
- Experimental Seafood Processing Laboratory, Coastal and Research Extension Center, Mississippi State University, Pascagoula, MS, USA
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Peters MH, Bastidas O, Kokron DS, Henze CE. Static all-atom energetic mappings of the SARS-Cov-2 spike protein and dynamic stability analysis of "Up" versus "Down" protomer states. PLoS One 2020; 15:e0241168. [PMID: 33170884 PMCID: PMC7654774 DOI: 10.1371/journal.pone.0241168] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 10/10/2020] [Indexed: 11/23/2022] Open
Abstract
The SARS-CoV-2 virion responsible for the current world-wide pandemic COVID-19 has a characteristic Spike protein (S) on its surface that embellishes both a prefusion state and fusion state. The prefusion Spike protein (S) is a large trimeric protein where each protomer may be in a so-called Up state or Down state, depending on the configuration of its receptor binding domain (RBD) within its distal, prefusion S1 domain. The Up state is believed to allow binding of the virion to ACE-2 receptors on human epithelial cells, whereas the Down state is believed to be relatively inactive or reduced in its binding behavior. We have performed detailed all-atom, dominant energy landscape mappings for noncovalent interactions (charge, partial charge, and van der Waals) of the SARS-CoV-2 Spike protein in its static prefusion state based on two recent and independent experimental structure publications. We included both interchain interactions and intrachain (domain) interactions in our mappings in order to determine any telling differences (different so-called “glue” points) between residues in the Up and Down state protomers. The S2 proximal, fusion domain demonstrated no appreciable energetic differences between Up and Down protomers, including interchain as well as each protomer’s intrachain, S1-S2 interactions. However, the S1 domain interactions across neighboring protomers, which include the RBD-NTD cross chain interactions, showed significant energetic differences between Up-Down and Down-Down neighboring protomers. This included, for example, a key RBD residue ARG357 in the Up-Down interaction and a three residue sequence ALA520-PRO521-ALA522, associated with a turn structure in the RBD of the Up state protomer, acting as a stabilizing interaction with the NTD of its neighbor protomer. Additionally, our intra chain dominant energy mappings within each protomer, identified a significant “glue” point or possible “latch” for the Down state protomer between the S1 subdomain, SD1, and the RBD domain of the same protomer that was completely missing in the Up state protomer analysis. Ironically, this dominant energetic interaction in the Down state protomer involved the backbone atoms of the same three residue sequence ALA520-PRO521-ALA522 of the RBD with the amino acid R-group of GLN564 in the SD1 domain. Thus, this same three residue sequence acts as a stabilizer of the RBD in the Up conformation through its interactions with its neighboring NTD chain and a kind of latch in the Down state conformation through its interactions with its own SD1 domain. The dominant interaction energy residues identified here are also conserved across reported variations of SARS-CoV-2, as well as the closely related virions SARS-Cov and the bat corona virus RatG13. We conducted preliminary molecular dynamics simulations across 0.1 μ seconds to see if this latch provided structural stability and indeed found that a single point mutation (Q564G) resulted in the latch releasing transforming the protomer from the Down to the Up state conformation. Full trimeric Spike protein studies of the same mutation across all protomers, however, did not exhibit latch release demonstrating the critical importance of interchain interactions across the S1 domain, including RBD-NTD neighboring chain interactions. Therapies aimed at disrupting these noncovalent interactions could be a viable route for the physico-chemical mitigation of this deadly virion.
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Affiliation(s)
- Michael H. Peters
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, Virginia, United States of America
- * E-mail:
| | - Oscar Bastidas
- College of Biological Sciences, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Daniel S. Kokron
- NASA Ames Research Center, Moffett Field, California, United Sates of America
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Omega-3 index and blood pressure responses to eating foods naturally enriched with omega-3 polyunsaturated fatty acids: a randomized controlled trial. Sci Rep 2020; 10:15444. [PMID: 32963294 PMCID: PMC7508802 DOI: 10.1038/s41598-020-71801-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 08/11/2020] [Indexed: 01/06/2023] Open
Abstract
Diets low in seafood omega-3 polyunsaturated fatty acids (PUFAs) are very prevalent. Such diets have recently been ranked as the sixth most important dietary risk factor—1.5 million deaths and 33 million disability-adjusted life-years worldwide are attributable to this deficiency. Wild oily fish stocks are insufficient to feed the world’s population, and levels of eicosapentaenoic acid and docosahexaenoic acid (DHA) in farmed fish have more than halved in the last 20 years. Here we report on a double-blinded, controlled trial, where 161 healthy normotensive adults were randomly allocated to eat at least three portions/week of omega-3-PUFA enriched (or control) chicken-meat, and to eat at least three omega-3-PUFA enriched (or control) eggs/week, for 6 months. We show that regular consumption of omega-3-PUFA enriched chicken-meat and eggs significantly increased the primary outcome, the red cell omega-3 index (mean difference [98.75% confidence interval] from the group that ate both control foods, 1.7% [0.7, 2.6]). Numbers of subjects with a very high-risk omega-3 index (index < 4%) were more than halved amongst the group that ate both enriched foods. Furthermore, eating the enriched foods resulted in clinically relevant reductions in diastolic blood pressure (− 3.1 mmHg [− 5.8, − 0.3]). We conclude that chicken-meat and eggs, naturally enriched with algae-sourced omega-3-PUFAs, may serve as alternative dietary sources of these essential micronutrients. Unlike many lifestyle interventions, long-term population health benefits do not depend on willingness of individuals to make long-lasting difficult dietary changes, but on the availability of a range of commonly eaten, relatively inexpensive, omega-3-PUFA enriched foods.
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Peters MH, Bastidas O, Kokron DS, Henze C. Static All-Atom Energetic Mappings of the SARS-Cov-2 Spike Protein with Potential Latch Identification of the Down State Protomer. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2020. [PMID: 32511362 PMCID: PMC7263490 DOI: 10.1101/2020.05.12.091090] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The SARS-Cov-2 virion responsible for the current world-wide pandemic Covid-19 has a characteristic Spike protein (S) on its surface that embellishes both a prefusion state and fusion state. The prefusion Spike protein (S) is a large trimeric protein where each protomer may be in a so-called Up state or Down state, depending on the configuration of its receptor binding domain (RBD). The Up state is believed to allow binding of the virion to ACE-2 receptors on human epithelial cells, whereas the Down state is believed to be relatively inactive or reduced in its binding behavior. We have performed detailed all-atom, dominant energy landscape mappings for noncovalent interactions (charge, partial charge, and van der Waals) of the SARS-Cov-2 Spike protein in its static prefusion state based on recent structural information. We included both interchain interactions and intrachain (domain) interactions in our mappings in order to determine any telling differences (different so-called “glue” points) between residues in the Up and Down state protomers. In general, the S2 or fusion machinery domain of S is relatively rigid with strong noncovalent interactions facilitated by helical secondary structures, whereas the S1 domain, which contains the RBD and N-terminal domain (NTD), is relatively more flexible and characterized by beta strand structural motifs. The S2 domain demonstrated no appreciable energetic differences between Up and Down protomers, including interchain as well as each protomer’s intrachain, S1–S2 interactions. However, the S1 domain interactions across neighboring protomers, which include the RBD-NTD cross chain interactions, showed significant energetic differences between Up-Down and Down-Down neighboring protomers. Surprisingly, the Up-Down, RBD-NTD interactions were overall stronger and more numerous than the Down-Down cross chain interactions, including the appearance of the three residue sequence ALA520-PRO521-ALA522 associated with a turn structure in the RBD of the Up state protomer. Additionally, our intrachain dominant energy mappings within each protomer, identified a significant “glue” point or possible “latch” for the Down state protomer between the S1 subdomain, SD1, and the RBD domain of the same protomer that was completely missing in the Up state protomer analysis. Ironically, this dominant energetic interaction in the Down state protomer involved the backbone atoms of the same three residue sequence ALA520-PRO521-ALA522 of the RBD with the R-group of GLN564 in the SD1 domain. Thus, this same three residue sequence acts as a stabilizer of the RBD in the Up conformation through its interactions with its neighboring NTD chain and a kind of latch in the Down state conformation through its interactions with its own SD1 domain. The dominant interaction energy residues identified here are also conserved across reported variations of SARS-Cov-2, as well as the closely related virions SARS-Cov and the bat corona virus RatG13. To help verify the potential latch for the Down state protomer, we conducted some preliminary molecular dynamic simulations that effectively turn off this specific latch glue point via a single point mutation of GLN564. Interestingly, the single point mutation lead to the latch releasing in less than a few nanoseconds, but the latch remained fixed in the wild state protomer for up to 0.1 microseconds that were simulated. Many more detailed studies are needed to understand the dynamics of the Up and Down states of the Spike protein, including the stabilizing chain-chain interactions and the mechanisms of transition from Down to Up state protomers. Nonetheless, static dominant energy landscape mappings and preliminary molecular dynamic studies given here may represent a useful starting point for more detailed dynamic analyses and hopefully an improved understanding of the structure-function relationship of this highly complex protein associated with COVID-19.
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Affiliation(s)
- Michael H Peters
- Virginia Commonwealth University, Department of Chemical and Life Science Engineering, 601 West Main St, Richmond, Virginia, United States of America
| | - Oscar Bastidas
- University of Minnesota, College of Biological Sciences, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Daniel S Kokron
- NASA Ames Research Center, Moffett Field, California, United Sates of America
| | - Christopher Henze
- NASA Ames Research Center, Moffett Field, California, United States of America
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