Rapid unfolding of pig pancreas α-amylase: Kinetics, activity and structure evolution

Zhang, Hai; Ye, Yu-Tong; Deng, Jun-Ling; Zhao, Peng; Mao, Yu-Fen; Chen, Zhongxiu

doi:10.1016/j.foodchem.2021.130795

Cited by 12 publications

(12 citation statements)

References 36 publications

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“…In addition, a rare Zn 2+ is present in Pf Amy that forms a tetrahedral configuration with residues His147, His152, and Cys166 in domain B and a water molecule next to Ca 2+ (Figure c). The side chains of His152 and Cys166 are located inside Pf Amy and form hydrophobic interactions (Figure d), and therefore, mutations at both sites may disrupt the hydrophobic environment and destabilize α-amylase . Hence, double K152H/A166C and triplicate K152H/A166C/E168H mutants of Te Amy were constructed.…”

Section: Resultsmentioning

confidence: 99%

High Production of Maltooligosaccharides in the Starch Liquefaction Process: A Study on the Hyperthermophilic Mechanism of α-Amylase

Lü

Dong

et al. 2023

J. Agric. Food Chem.

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The efficient production of high-value-added bioproducts from starchy substances requires α-amylases with hyperthermophilic properties for industrial starch liquefaction. In this study, two hyperthermophilic α-amylases with significant differences in thermostability, PfAmy and TeAmy, were comparatively studied through structural analysis, domain swapping, and site-directed mutagenesis, finding that three residues, His152, Cys166, and His168, located in domain B were the main contributors to hyperthermostability. The effects of these three residues were strongly synergistic, causing the optimum temperature for the mutant K152H/A166C/E168H of TeAmy to shift to 95–100 °C and stabilize at 90 °C without Ca2+. Compared to PfAmy and TeAmy, the mutant K152H/A166C/E168H, respectively, exhibited 1.7- and 2.5-times higher starch hydrolysis activity at 105 °C and pH 5.5 (10411 ± 70 U/mg) and released 1.1- and 1.7-times more maltooligosaccharides from 1% starch. This work has interpreted the hyperthermophilic mechanism of α-amylase and thereby providing a potential candidate for the efficient industrial conversion of starch to bioproducts.

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Section: Resultsmentioning

confidence: 99%

High Production of Maltooligosaccharides in the Starch Liquefaction Process: A Study on the Hyperthermophilic Mechanism of α-Amylase

Lü

Dong

et al. 2023

J. Agric. Food Chem.

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“…The differential spectrum was automatically smoothed for peak resolution. Gaussian fitting of the peak area was performed to quantify the hydrogen bond ratio of the water structure ( C f / C p ), in which the content of “full” hydrogen bonds was recorded as C f and that of the “partial” hydrogen bonds was recorded as C p . , …”

Section: Methodsmentioning

confidence: 99%

“…Stopped-flow spectroscopy can record information for a rapid response from 0.001 to 0.01 s in chemical reactions. This technique has been used to study the dynamics of intermolecular interactions, such as protein–protein binding, protein–ligand binding, electron transfer, protein folding, and enzymatic reactions. – It has also been used to study the binding of the epidermal growth factor to its receptors . However, the interaction between sweet taste receptors and sweeteners has not been studied via stopped-flow spectroscopy.…”

Section: Introductionmentioning

confidence: 99%

Rapid Kinetic Interactions of Sugar and Sugar Alcohol with Sweet Taste Receptors on Live Cells Using Stopped-Flow Spectroscopy

Deng,

Tang,

et al. 2023

J. Agric. Food Chem.

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The subjective measurement of the dynamic perception of sweetness is a problem in food science. Herein, the rapid interactions of sugars and sugar alcohols with sweet taste receptors on living cells on a millisecond timescale were studied via stopped-flow fluorescence spectroscopy. According to the rapid-kinetic parameters, sweeteners were divided into two groups. Sweeteners in group I disrupted the hydrogen bond network structure of water, and the apparent rate constant (k obs) was in the range of 0.45–0.6 s–1. Sweeteners in group II promoted the hydrogen bond formation of water, and the k obs was mostly in the range of 0.6–0.75 s–1. For most sweeteners, the k obs of cell responses was negatively correlated with the apparent specific volume of sweeteners. The differences in the cellular responses may be attributed to the disturbance in the water structure. Experimental results showed that the kinetic parameters of sweet cell responses reflected the dynamic perception of sweetness. Rapid kinetics, solution thermodynamic analysis, and water structure analysis enriched the physicochemical study of the sweetness mechanism and can be used to objectively evaluate the dynamic perception of sweetness.

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“…Cornstarch is composed of amylose (AM) and amylopectin (AP), and amylopectin not only contains α-1, 4-glucosidic bonds but also α-1, 6-glucosidic bonds. Animal pancreases only secrete α-amylase to degrade α-1, 4-glucosidic bonds, while amylopectin can only be hydrolyzed by amylopectase [ 2 ]. Corn has a high concentration of insoluble non-starch polysaccharides (NSP), such as xylan and cellulose [ 3 ], which limit the ability of digestive enzymes to access and fully digest the starch and protein components enclosed within the plant cells.…”

Section: Introductionmentioning

confidence: 99%

Supplemental Enzyme and Probiotics on the Growth Performance and Nutrient Digestibility of Broilers Fed with a Newly Harvested Corn Diet

Luo

Wang²,

Chen³

et al. 2022

Animals

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A new grain phenomenon happens in newly harvested corn because of its high content of anti-nutritional factors (ANFs), which can cause low nutrient digestibility and diarrhea in animals. Enzymes and probiotics have been shown to relieve the negative effect of ANFs for animals. The purpose of this study was to investigate the effect of enzymes and probiotics on the performance and nutrient digestibility of broilers, fed with newly harvested corn diets. A total of 624 Arbor Acres Plus male broiler chickens were randomly divided into eight treatment groups (A: normal corn diet, CT: newly harvested corn diet, DE: newly harvested corn diet + glucoamylase, PT: newly harvested corn diet + protease, XL: newly harvested corn diet + xylanase, BCC: newly harvested corn diet + Pediococcus acidilactici BCC-1, DE + PT: newly harvested corn diet + glucoamylase + protease, XL + BCC: newly harvested corn diet + xylanase + Pediococcus acidilactici BCC-1). Each group was divided into six replicates, with 13 birds each. On day 21, growth performance, nutrient digestibility, and digestive enzyme activity were measured. Compared with the normal corn diet (PC), the newly harvested corn diet (NC) produced shorter digesta emptying time (p = 0.015) and increased visual fecal water content (p = 0.002) of broilers, however, there was no effect on performance. Compared to the newly harvested corn diet (NC), supplemental enzyme of DE increased the activity of chymotrypsin (p = 0.016), however, no differences in the digestibility of three kinds of organic matter, digesta emptying time, visual fecal water content, or performance were found. Supplemental protease (PT) significantly increased digesta emptying time (p = 0.004) and decreased the activity of maltase (p = 0.007). However, it had no effect on the digestibility of three kinds of organic matter or the performance of broilers. Supplemental xylanase (XL) decreased the activity of amylase (p = 0.006) and maltase (p < 0.001); however, it had no effect on digesta emptying time, visual fecal water content, the digestibility of three kinds of organic matter, or performance of broilers. Supplemental DE, combined with PT (DE + PT), increased the digesta emptying time (p = 0.016) while decreasing the visual fecal water content (p = 0.011), and the activity of amylase (p = 0.011), lipase (p = 0.021), and maltase (p < 0.001), however, there was no effect on performance. Supplemental BCC individually decreased the activity of amylase (p = 0.024) and maltase (p < 0.001), however, it increased the activity of trypsin (p < 0.001) and tended to improve feed conversion ratio (FCR) (p = 0.081). Supplemental BCC-1, combined with XL (XL + BCC), increased the activity of trypsin (p = 0.001) but decreased the activity of amylase (p = 0.013), lipase (p = 0.019), and maltase (p < 0.001). Pediococcus acidilactici BCC-1 (109 cfu/kg), protease (800,000 U/g) individually, or protease (800,000 U/g) in combination with glucoamylase (800,000 U/g) were supplemented in newly harvested corn diets for growing broilers. Hence, this study mainly explores the alleviation effect of enzyme and probiotics on the negative phenomenon caused by the utilization of newly harvested corn in broilers and provides a better solution for the utilization of newly harvested corn in production practice.

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Rapid unfolding of pig pancreas α-amylase: Kinetics, activity and structure evolution

Cited by 12 publications

References 36 publications

High Production of Maltooligosaccharides in the Starch Liquefaction Process: A Study on the Hyperthermophilic Mechanism of α-Amylase

High Production of Maltooligosaccharides in the Starch Liquefaction Process: A Study on the Hyperthermophilic Mechanism of α-Amylase

Rapid Kinetic Interactions of Sugar and Sugar Alcohol with Sweet Taste Receptors on Live Cells Using Stopped-Flow Spectroscopy

Supplemental Enzyme and Probiotics on the Growth Performance and Nutrient Digestibility of Broilers Fed with a Newly Harvested Corn Diet

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