Digestive α-amylases from Tecia solanivora larvae (Lepidoptera: Gelechiidae): response to pH, temperature and plant amylase inhibitors

AbstractThe biochemical properties of the digestive alpha-amylase from Tecia solanivora larvae, an important and invasive insect pest of potato (Solanum tuberosum), were studied. This insect has three major digestive α-amylases with isoelectric points 5.30, 5.70 and 5.98, respectively, which were separated using native and isoelectric focusing gels. The alpha-amylase activity has an optimum pH between 7.0 and 10.0 with a peak at pH 9.0. The enzymes are stable when heated to 50°C and were inhibited by proteinaceous inhibitors from Phaseolus coccineus (70% inhibition) and P. vulgaris cv. Radical (87% inhibition) at pH 6.0. The inhibitors present in an amaranth hybrid inhibited 80% of the activity at pH 9.0. The results show that the alpha-amylase inhibitor from amaranth seeds may be a better candidate to make genetically-modified potatoes resistant to this insect than inhibitors from common bean seeds.

Download Full-text

Multiple forms of immunoreactive renin in human adrenocortical tumour tissue from patients with primary aldosteronism

Clinical Science ◽

10.1042/cs0720699 ◽

1987 ◽

Vol 72 (6) ◽

pp. 699-704 ◽

Cited By ~ 2

Author(s):

Kenji Mizuno ◽

Motoko Ojima ◽

Shigeatsu Hashimoto ◽

Makio Tani ◽

Susumu Niimura ◽

...

Keyword(s):

Rat Plasma ◽

Biochemical Properties ◽

Zona Glomerulosa ◽

Multiple Forms ◽

Angiotensin I ◽

Isoelectric Points ◽

Optimum Ph ◽

Glomerulosa Cells ◽

Adrenocortical Tumour ◽

Zona Glomerulosa Cells

1. There is increasing evidence which suggests that the adrenal gland contains the renin–angiotensin cycle. The localization of renin has been reported to be mainly in the zona glomerulosa rather than the fasciculata medullary portion. In the present study we have investigated extracts from aldosteronomas (n = 3), which are believed to derive from the zona glomerulosa cells. In addition, we have attempted to characterize the biochemical properties of the adrenal renin. 2. Sizable quantities of renin-like activity (32.0 ± 7.7 ng of angiotensin I generated h−1 mg−1 of protein, mean ± SEM) were detected in the extracts. This renin-like activity was inhibited by anti-renin antibody raised against pure renin (mean, 95% of the total renin-like activity), indicating that it was not due to the non-specific action of proteases such as cathepsin D. 3. The optimum pH of the tissue renin-like enzyme was 6.0 for rat plasma substrate. Differences were found, however, in the molecular mass (36000, 37000, 44000 and 48000), binding to concanavalin A and isoelectric points (4.40, 4.68 and 5.00). 4. These results confirm the existence of specific renin in aldosteronoma. Renin microheterogeneity could be evidence for local production of the enzyme.

Download Full-text

Inhibition of Pancreatic α-Amylase Activity by a Weight-Loss Herbal Formula RCM-107

10.20944/preprints201907.0284.v1 ◽

2019 ◽

Author(s):

Shiqi Luo ◽

George Lenon ◽

Harsharn Gill ◽

Andrew Hung ◽

Daniel A. Dias ◽

...

Keyword(s):

Weight Loss ◽

Amylase Activity ◽

Synergistic Effects ◽

Glycaemic Index ◽

Alpha Amylase ◽

Inhibitory Effects ◽

Active Compounds ◽

Residue Contact ◽

The Individual ◽

Amylase Inhibitors

Reducing carbohydrates digestion by having low glycaemic index (GI) foods has been linked to weight loss. Inhibiting related enzymes is an alternative way to decrease carbohydrate digestion. RCM-107, an eight-herb formula that is modified from the RCM-104, has indicated significant weight-loss action in clinical trials. However, no research has been conducted to study its effect on the activity of porcine pancreatic alpha-amylase (PPA), which is involved in carbohydrate absorption. In this paper, we used fluorescence PPA inhibition assay to investigate the inhibitory effects of RCM-107 and the individual herbs present in this herbal mixture on amylase activity. Subsequently, molecular docking predicted the key active compounds that may be responsible for the enzyme inhibition. According to our results, both the RCM-107 formula and several individual herbs displayed α-amylase inhibitory effects. Also, marginal synergistic effects of RCM-107 were also detected. In addition, alisol B, (-)-epigallocatechin-3-gallate (EGCG) and plantagoside have been predicted as the key active compounds that may be responsible for the α-amylase inhibition effect of RCM-107 according to inter-residue contact analysis. Finally, Glu233, Gln63, His305, Asp300 and Tyr151 are predicted to be markers of important areas with which potential amylase inhibitors would interact.

Download Full-text

The activities of amylases and α-amylase inhibitor in wide-range herbicide resistant wheat lines

Czech Journal of Food Sciences ◽

10.17221/125/2009-cjfs ◽

2010 ◽

Vol 28 (No. 3) ◽

pp. 217-224

Author(s):

M. Nagy-Gasztonyi ◽

A. Nagy ◽

E. Németh-SZerdahelyi ◽

J. Pauk ◽

É. Gelencsér

Keyword(s):

Amylase Activity ◽

Triticum Aestivum L ◽

Transgenic Wheat ◽

Alpha Amylase ◽

Non Profit ◽

Amylase Inhibitor ◽

Wide Range ◽

Transgenic Lines ◽

Alpha Amylase Inhibitor ◽

Wheat Lines

The activities of total amylase, α-amylase, and α-amylase inhibitor in the albumin-globulin fractions of isogenic non transgenic control (CY 45) and ppt (phosphinothrichin) resistant transgenic spring wheat (Triticum aestivum L.) lines (T106, T116, T117, T124, T128, T129) were studied in two subsequent years. The plants were either sprayed with a selective herbicide Granstar (G), a wide range herbicide Finale 14 SL (F), or were grown without spraying (Q). Samples were obtained from field trial experiments of the Cereal Research Non Profit Co (Szeged, Hungary). Our results showed an increased trend in total amylase activity of untreated transgenic wheat lines in comparison with non transgenic wheat. The herbicide treatments enhanced the total amylase activity in both transgenic and non transgenic wheat samples. The changes in α-amylase inhibitor activity showed the same trend as that observed in total amylase activity in transgenic lines.

Download Full-text