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Molecules (Basel, Switzerland) Apr 2023Maltooligosaccharides (MOS) are homooligosaccharides that consist of 3-10 glucose molecules linked by α-1,4 glycosidic bonds. As they have physiological functions, they... (Review)
Review
Maltooligosaccharides (MOS) are homooligosaccharides that consist of 3-10 glucose molecules linked by α-1,4 glycosidic bonds. As they have physiological functions, they are commonly used as ingredients in nutritional products and functional foods. Many researchers have investigated the potential applications of MOS and their derivatives in the pharmaceutical industry. In this review, we summarized the properties and methods of fabricating MOS and their derivatives, including sulfated and non-sulfated alkylMOS. For preparing MOS, different enzymatic strategies have been proposed by various researchers, using α-amylases, maltooligosaccharide-forming amylases, or glycosyltransferases as effective biocatalysts. Many researchers have focused on using immobilized biocatalysts and downstream processes for MOS production. This review also provides an overview of the current challenges and future trends of MOS production.
Topics: Amylases; Oligosaccharides; alpha-Amylases; Glucose; Biocatalysis
PubMed: 37050044
DOI: 10.3390/molecules28073281 -
Brazilian Journal of Medical and... Feb 2017Currently, the potential for cardiovascular (CV) stress-induced risk is primarily based on the theoretical (obvious) side effects of stress on the CV system. Salivary... (Review)
Review
Currently, the potential for cardiovascular (CV) stress-induced risk is primarily based on the theoretical (obvious) side effects of stress on the CV system. Salivary cortisol and α-amylase, produced respectively by the hypothalamus-pituitary-adrenal (HPA) axis and the sympathetic-adrenomedullary (SAM) system during stress response, are still not included in the routine evaluation of CV risk and require additional and definitive validation. Therefore, this article overviews studies published between 2010 and 2015, in which salivary cortisol and α-amylase were measured as stress biomarkers to examine their associations with CV/CMR (cardiometabolic risk) clinical and subclinical indicators. A comprehensive search of PubMed, Web of Science and Scopus electronic databases was performed, and 54 key articles related to the use of salivary cortisol and α-amylase as subclinical indicators of stress and CV/CMR factors, including studies that emphasized methodological biases that could influence the accuracy of study outcomes, were ultimately identified. Overall, the biological impact of stress measured by salivary cortisol and α-amylase was associated with CV/CMR factors. Results supported the use of salivary cortisol and α-amylase as potential diagnostic tools for detecting stress-induced cardiac diseases and especially to describe the mechanisms by which stress potentially contributes to the pathogenesis and outcomes of CV diseases.
Topics: Cardiovascular Diseases; Humans; Hydrocortisone; Hypothalamo-Hypophyseal System; Pituitary-Adrenal System; Saliva; Stress, Psychological; alpha-Amylases
PubMed: 28177057
DOI: 10.1590/1414-431X20165577 -
European Journal of Biochemistry Jan 2002Insect pests and pathogens (fungi, bacteria and viruses) are responsible for severe crop losses. Insects feed directly on the plant tissues, while the pathogens lead to... (Review)
Review
Insect pests and pathogens (fungi, bacteria and viruses) are responsible for severe crop losses. Insects feed directly on the plant tissues, while the pathogens lead to damage or death of the plant. Plants have evolved a certain degree of resistance through the production of defence compounds, which may be aproteic, e.g. antibiotics, alkaloids, terpenes, cyanogenic glucosides or proteic, e.g. chitinases, beta-1,3-glucanases, lectins, arcelins, vicilins, systemins and enzyme inhibitors. The enzyme inhibitors impede digestion through their action on insect gut digestive alpha-amylases and proteinases, which play a key role in the digestion of plant starch and proteins. The natural defences of crop plants may be improved through the use of transgenic technology. Current research in the area focuses particularly on weevils as these are highly dependent on starch for their energy supply. Six different alpha-amylase inhibitor classes, lectin-like, knottin-like, cereal-type, Kunitz-like, gamma-purothionin-like and thaumatin-like could be used in pest control. These classes of inhibitors show remarkable structural variety leading to different modes of inhibition and different specificity profiles against diverse alpha-amylases. Specificity of inhibition is an important issue as the introduced inhibitor must not adversely affect the plant's own alpha-amylases, nor the nutritional value of the crop. Of particular interest are some bifunctional inhibitors with additional favourable properties, such as proteinase inhibitory activity or chitinase activity. The area has benefited from the recent determination of many structures of alpha-amylases, inhibitors and complexes. These structures highlight the remarkable variety in structural modes of alpha-amylase inhibition. The continuing discovery of new classes of alpha-amylase inhibitor ensures that exciting discoveries remain to be made. In this review, we summarize existing knowledge of insect alpha-amylases, plant alpha-amylase inhibitors and their interaction. Positive results recently obtained for transgenic plants and future prospects in the area are reviewed.
Topics: Animals; Enzyme Inhibitors; Insecta; Plants; alpha-Amylases
PubMed: 11856298
DOI: 10.1046/j.0014-2956.2001.02656.x -
International Journal of Molecular... Jan 2019Alpha-amylase, the major form of amylase with secondary carbohydrate binding sites, is a crucial enzyme throughout the growth period and life cycle of angiosperm. In... (Review)
Review
Alpha-amylase, the major form of amylase with secondary carbohydrate binding sites, is a crucial enzyme throughout the growth period and life cycle of angiosperm. In rice, alpha-amylase isozymes are critical for the formation of the storage starch granule during seed maturation and motivate the stored starch to nourish the developing seedling during seed germination which will directly affect the plant growth and field yield. Alpha-amylase has not yet been studied intensely to understand its classification, structure, expression trait, and expression regulation in rice and other crops. Among the 10-rice alpha-amylases, most were exclusively expressed in the developing seed embryo and induced in the seed germination process. During rice seed germination, the expression of alpha-amylase genes is known to be regulated negatively by sugar in embryos, however positively by gibberellin (GA) in endosperm through competitively binding to the specific promoter domain; besides, it is also controlled by a series of other abiotic or biotic factors, such as salinity. In this review, we overviewed the research progress of alpha-amylase with focus on seed germination and reflected on how in-depth work might elucidate its regulation and facilitate crop breeding as an efficient biomarker.
Topics: Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Plant; Germination; Multigene Family; Oryza; Phenotype; Plant Development; Quantitative Trait, Heritable; Seeds; Structure-Activity Relationship; alpha-Amylases
PubMed: 30669630
DOI: 10.3390/ijms20020450 -
G3 (Bethesda, Md.) Feb 2020The subfamily GH13_1 of alpha-amylases is typical of Fungi, but it is also found in some unicellular eukaryotes (, Amoebozoa, choanoflagellates) and non-bilaterian...
The subfamily GH13_1 of alpha-amylases is typical of Fungi, but it is also found in some unicellular eukaryotes (, Amoebozoa, choanoflagellates) and non-bilaterian Metazoa. Since a previous study in 2007, GH13_1 amylases were considered ancestral to the Unikonts, including animals, except Bilateria, such that it was thought to have been lost in the ancestor of this clade. The only alpha-amylases known to be present in Bilateria so far belong to the GH13_15 and 24 subfamilies (commonly called bilaterian alpha-amylases) and were likely acquired by horizontal transfer from a proteobacterium. The taxonomic scope of Eukaryota genomes in databases has been greatly increased ever since 2007. We have surveyed GH13_1 sequences in recent data from ca. 1600 bilaterian species, 60 non-bilaterian animals and also in unicellular eukaryotes. As expected, we found a number of those sequences in non-bilaterians: Anthozoa (Cnidaria) and in sponges, confirming the previous observations, but none in jellyfishes and in Ctenophora. Our main and unexpected finding is that such fungal (also called Dictyo-type) amylases were also consistently retrieved in several bilaterian phyla: hemichordates (deuterostomes), brachiopods and related phyla, some molluscs and some annelids (protostomes). We discuss evolutionary hypotheses possibly explaining the scattered distribution of GH13_1 across bilaterians, namely, the retention of the ancestral gene in those phyla only and/or horizontal transfers from non-bilaterian donors.
Topics: Basidiomycota; Evolution, Molecular; Gene Transfer, Horizontal; Genes, Fungal; Introns; Phylogeny; Transformation, Genetic; alpha-Amylases
PubMed: 31810981
DOI: 10.1534/g3.119.400826 -
Current Neuropharmacology 2022Alzheimer's disease (AD), the most common form of dementia, is pathologically characterized by the deposition of amyloid-β plaques and the formation of neurofibrillary... (Review)
Review
Alzheimer's disease (AD), the most common form of dementia, is pathologically characterized by the deposition of amyloid-β plaques and the formation of neurofibrillary tangles. In a neurodegenerative brain, glucose metabolism is also impaired and considered as one of the key features in AD patients. The impairment causes a reduction in glucose transporters and the uptake of glucose as well as alterations in the specific activity of glycolytic enzymes. Recently, it has been reported that α-amylase, a polysaccharide-degrading enzyme, is present in the human brain. The enzyme is known to be associated with various diseases such as type 2 diabetes mellitus and hyperamylasaemia. With this information at hand, we hypothesize that α-amylase could have a vital role in the demented brains of AD patients. This review aims to shed insight into the possible link between the expression levels of α-amylase and AD. Lastly, we also cover the diverse role of amylase inhibitors and how they could serve as a therapeutic agent to manage or stop AD progression.
Topics: Alzheimer Disease; Amyloid beta-Peptides; Biomarkers; Brain; Diabetes Mellitus, Type 2; Glucose; Humans; Plaque, Amyloid; alpha-Amylases
PubMed: 34951390
DOI: 10.2174/1570159X20666211223124715 -
Journal of the American Chemical Society Feb 2021Amylases are key enzymes in the processing of starch in many kingdoms of life. They are important catalysts in industrial biotechnology where they are applied in, among...
Amylases are key enzymes in the processing of starch in many kingdoms of life. They are important catalysts in industrial biotechnology where they are applied in, among others, food processing and the production of detergents. In man amylases are the first enzymes in the digestion of starch to glucose and arguably also the preferred target in therapeutic strategies aimed at the treatment of type 2 diabetes patients through down-tuning glucose assimilation. Efficient and sensitive assays that report selectively on retaining amylase activities irrespective of the nature and complexity of the biomaterial studied are of great value both in finding new and effective human amylase inhibitors and in the discovery of new microbial amylases with potentially advantageous features for biotechnological application. Activity-based protein profiling (ABPP) of retaining glycosidases is inherently suited for the development of such an assay format. We here report on the design and synthesis of 1,6--cyclophellitol-based pseudodisaccharides equipped with a suite of reporter entities and their use in ABPP of retaining amylases from human saliva, murine tissue as well as secretomes from fungi grown on starch. The activity and efficiency of the inhibitors and probes are substantiated by extensive biochemical analysis, and the selectivity for amylases over related retaining endoglycosidases is validated by structural studies.
Topics: Animals; Enzyme Assays; Humans; Mice; Saliva; alpha-Amylases
PubMed: 33497208
DOI: 10.1021/jacs.0c13059 -
Microbial Cell Factories Jul 2017Amylase plays an important role in biotechnology industries, and Gram-positive bacterium Bacillus subtilis is a major host to produce heterogeneous α-amylases. However,... (Review)
Review
Amylase plays an important role in biotechnology industries, and Gram-positive bacterium Bacillus subtilis is a major host to produce heterogeneous α-amylases. However, the secretion stress limits the high yield of α-amylase in B. subtilis although huge efforts have been made to address this secretion bottleneck. In this question-oriented review, every effort is made to answer the following questions, which look simple but are long-standing, through reviewing of literature: (1) Does α-amylase need a specific and dedicated chaperone? (2) What signal sequence does CsaA recognize? (3) Does CsaA require ATP for its operation? (4) Does an unfolded α-amylase is less soluble than a folded one? (5) Does α-amylase aggregate before transporting through Sec secretion system? (6) Is α-amylase sufficient stable to prevent itself from misfolding? (7) Does α-amylase need more disulfide bonds to be stabilized? (8) Which secretion system does PrsA pass through? (9) Is PrsA ATP-dependent? (10) Is PrsA reused after folding of α-amylase? (11) What is the fate of PrsA? (12) Is trigger factor (TF) ATP-dependent? The literature review suggests that not only the most of those questions are still open to answers but also it is necessary to calculate ATP budget in order to better understand how B. subtilis uses its energy for production and secretion.
Topics: Adenosine Triphosphate; Bacillus subtilis; Bacterial Proteins; Disulfides; Gene Expression Regulation, Bacterial; Lipoproteins; Membrane Proteins; Molecular Chaperones; Protein Folding; Protein Sorting Signals; Recombinant Proteins; Solubility; alpha-Amylases
PubMed: 28724440
DOI: 10.1186/s12934-017-0738-1 -
FEBS Letters Jun 1992The recent state of the knowledge of properties and structure of alpha-amylases is reviewed with the aim of elucidation the basis for their stabilization. Three... (Review)
Review
The recent state of the knowledge of properties and structure of alpha-amylases is reviewed with the aim of elucidation the basis for their stabilization. Three principal ways for obtaining stable alpha-amylases (isolation of enzymes from extremophiles, production of extremophilic enzymes in mesophiles, and modification of mesophilic enzymes) are discussed separately. Detailed experimental examples are given for modification approaches.
Topics: Enzyme Stability; alpha-Amylases
PubMed: 1618293
DOI: 10.1016/0014-5793(92)80575-2 -
BioMed Research International 2021The leaves of have been used in the management of diabetes mellitus in Ethiopian folk medicine. Thus, this study is aimed at investigating the -amylase and -glucosidase...
BACKGROUND
The leaves of have been used in the management of diabetes mellitus in Ethiopian folk medicine. Thus, this study is aimed at investigating the -amylase and -glucosidase inhibitory and antioxidant activities of the crude extract and solvent fractions of leaves.
METHODS
The -amylase and -glucosidase inhibitory and antioxidant activities of the plant extract were assessed using 3,5-dinitrosalicylic acid (DNSA), p-nitro-phenyl-a-D glucopyranoside (p-NPG), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays, respectively. Each value of percent inhibition of -amylase, -glucosidase, and DPPH scavenging effect was presented as means ± SEM ( = 3).
RESULTS
The -amylase inhibitory activity of the crude extract and solvent fractions was found to be concentration-dependent. The strongest activity was exhibited by the crude extract at the highest concentration with a percentage inhibition of 74.52% (IC, 14.52 g/ml) followed by water fraction 68.24% (IC, 16.31 g/ml), ethyl acetate fraction 61.57% (IC, 18.73 g/ml), and chloroform fraction 56.87% (IC, 21.57 g/ml) of leaves. In the -glucosidase inhibition assay, the maximum activity was exhibited by the fraction 62.54% (IC, 11.67 g/ml) followed by ethyl acetate fraction 54.97% (IC, 15.89 g/ml), crude extract 46.79% (IC, >16.5 g/ml), and chloroform fraction 36.44% (IC, >16.5 g/ml). In the antioxidant assay, the crude extract exhibited the highest antioxidant activity 86.36% (IC, 10.25 g/ml) followed by water fraction 78.59% (IC, 13.86 g/ml), ethyl acetate fraction 71.58% (IC, 16.34 g/ml), and chloroform fraction 63.65% (IC, 18.83 g/ml).
CONCLUSION
This study has revealed that leaves possess noticeable -amylase and -glucosidase inhibitory and antioxidant activities.
Topics: Antioxidants; Glycoside Hydrolase Inhibitors; Phytochemicals; Plant Extracts; Plant Leaves; Rosaceae; Solvents; alpha-Amylases; alpha-Glucosidases
PubMed: 33987444
DOI: 10.1155/2021/6652777