scholarly journals Substrate selectivity of C-terminal sucrase isomaltase and maltase glucoamylase

2014 ◽  
Vol 70 (a1) ◽  
pp. C813-C813
Author(s):  
Kyra Jones ◽  
David Rose
Keyword(s):  
Small Intestine ◽  
Substrate Specificity ◽  
Type Ii Diabetes ◽  
Serum Insulin ◽  
Substrate Selectivity ◽  
Type Ii ◽  
Significant Component ◽  
Human Diet ◽  
Catalytic Subunits ◽  
Free Glucose

Carbohydrates make up a significant component of the human diet. One approach to controlling blood glucose and serum insulin levels in individuals with type II diabetes is inhibition of intestinal α-glucosidases and pancreatic α-amylases. Two intestinal α-glucosidases, sucrase isomaltase (SI) and maltase glucoamylase (MGAM), are responsible for the final step of starch hydrolysis in mammals in the small intestine: the release of free glucose. Each enzyme consists of two catalytic subunits: N-terminal sucrase isomaltase (ntSI) and C-terminal sucrase isomaltose (ctSI); and N-terminal maltase glucoamylase (ntMGAM) and C-terminal maltase glucoamylase (ctMGAM). Here, residues hypothesized to impact substrate specificity of ctSI and ctMGAM will be presented, enhancing our understanding of the functionality of these enzymatic subunits as well as their overlapping substrate specificity.

scholarly journals Kinetic, Structural, and Mutational Analysis of Acyl-CoA Carboxylase From Thermobifida fusca YX

2021 ◽  
Vol 7 ◽  
Author(s):  
Kiran-Kumar Shivaiah ◽  
Bryon Upton ◽  
Basil J. Nikolau
Keyword(s):  
Substrate Specificity ◽  
Quaternary Structure ◽  
Mutational Analysis ◽  
Streptomyces Coelicolor ◽  
Thermobifida Fusca ◽  
Substrate Selectivity ◽  
Acetyl Coa ◽  
Catalytic Subunits ◽  
Chain Acyl

Acyl-CoA carboxylases (AcCCase) are biotin-dependent enzymes that are capable of carboxylating more than one short chain acyl-CoA substrate. We have conducted structural and kinetic analyses of such an AcCCase from Thermobifida fusca YX, which exhibits promiscuity in carboxylating acetyl-CoA, propionyl-CoA, and butyryl-CoA. The enzyme consists of two catalytic subunits (TfAcCCA and TfAcCCB) and a non-catalytic subunit, TfAcCCE, and is organized in quaternary structure with a A6B6E6 stoichiometry. Moreover, this holoenzyme structure appears to be primarily assembled from two A3 and a B6E6 subcomplexes. The role of the TfAcCCE subunit is to facilitate the assembly of the holoenzyme complex, and thereby activate catalysis. Based on prior studies of an AcCCase from Streptomyces coelicolor, we explored whether a conserved Asp residue in the TfAcCCB subunit may have a role in determining the substrate selectivity of these types of enzymes. Mutating this D427 residue resulted in alterations in the substrate specificity of the TfAcCCase, increasing proficiency for carboxylating acetyl-CoA, while decreasing carboxylation proficiency with propionyl-CoA and butyryl-CoA. Collectively these results suggest that residue D427 of AcCCB subunits is an important, but not sole determinant of the substrate specificity of AcCCase enzymes.

scholarly journals A SYNERGISTIC INSULINOTROPIC EFFECT OF GREEN TEA EXTRACT AND POMEGRANATE EXTRACT WITH ROSIGLITAZONE: BOTH IN VIVO AND IN VITRO EXPERIMENT

2020 ◽  
pp. 96-99
Author(s):  
REKHA S ◽  
CHANDRASHEKHARA S
Keyword(s):  
Green Tea ◽  
Type Ii Diabetes ◽  
Body Weight Gain ◽  
Serum Insulin ◽  
In Vivo Studies ◽  
Albino Rats ◽  
Type Ii ◽  
Insulinotropic Effect

Objective: Scientists have growing interest in traditional medicinal plants as they contain active ingredients for the treatment of various diseases. Tea is one of the most popular beverages worldwide. The variety of tea and tea extracts in the market has different polyphenol profiles, which are the bioactive chemical entities. We performed a direct comparison between Thea sinensis, green tea extracts (GTEs), and Punica granatum peel powder (PGPP), which have been chemically well characterized in a type II diabetic mouse model. Methods: We conducted both in vivo and in vitro experiments in the present paper. In vivo studies were carried out on male Swiss albino rats having type II diabetes, induced by single intravenous injection of streptozotocin (0.7 mg/Kg i.m.) and IDDM rats received either PGPP (200 mg/kg) or GTE (100 mg/kg) as a single oral dose. After the above result, the extracts were further subjected to know the effect of insulin secretion by RIN-5F cells providing confirmation of insulinotropic effect. Results: The results revealed that both PGPP and GTE substantially lowered blood glucose levels and ameliorated glucose intolerance, both were effective in antihyperglycemic activity and in lowering body weight gain. Serum insulin levels significantly increased in GTE group as well as in PGPP group, suggesting that they were exerting hypoglycemic effects through different pathways. Conclusion: Synergistic action of PGPP and GTE is an effective alternative for the treatment of type II diabetes through the regeneration of β cells of pancreas.

Serum Insulin and Glucose Concentrations in People at Risk for Type II Diabetes: A comparative study of African Americans and Nigerians

Diabetes Care ◽  
1993 ◽  
Vol 16 (10) ◽  
pp. 1367-1375 ◽  
Author(s):  
K. Osei ◽  
D. A. Cottrell ◽  
C. A. Adenuwon ◽  
E. C. Ezenwaka ◽  
A. O. Akanji ◽  
...  
Keyword(s):  
At Risk ◽  
African Americans ◽  
Comparative Study ◽  
Type Ii Diabetes ◽  
Serum Insulin ◽  
Type Ii

scholarly journals A Critical Role of Hepatic GABA in The Metabolic Dysfunction and Hyperphagia of Obesity

2020 ◽  
Author(s):  
Caroline. E. Geisler ◽  
Susma. Ghimire ◽  
Stephanie. M. Bruggink ◽  
Kendra E. Miller ◽  
Savanna. N. Weninger ◽  
...  
Keyword(s):  
Type Ii Diabetes ◽  
Serum Insulin ◽  
Critical Role ◽  
Metabolic Dysfunction ◽  
Type Ii ◽  
Obese Mice ◽  
Hepatic Lipid Accumulation ◽  
Gaba Production ◽  
Hepatic Synthesis

AbstractHepatic lipid accumulation is a hallmark of type II diabetes (T2D) and associated with hyperinsulinemia, insulin resistance, and hyperphagia. Hepatic synthesis of GABA, catalyzed by GABA-transaminase (GABA-T), is upregulated in obese mice. To assess the role of hepatic GABA production in obesity-induced metabolic and energy dysregulation, we treated mice with two pharmacologic GABA-T inhibitors and knocked down hepatic GABA-T expression using an antisense oligonucleotide. Hepatic GABA-T inhibition and knockdown decreased basal hyperinsulinemia and hyperglycemia, and improved glucose intolerance. GABA-T knockdown improved insulin sensitivity assessed by hyperinsulinemic-euglycemic clamps in obese mice. Hepatic GABA-T knockdown also decreased food intake and induced weight loss without altering energy expenditure in obese mice. Data from people with obesity support the notion that hepatic GABA production and transport are associated with serum insulin, HOMA-IR, T2D, and BMI. These results support a key role for hepatocyte GABA production in the dysfunctional glucoregulation and feeding behavior associated with obesity.

Coadministration of alloxan and nicotinamide in rats produces biochemical changes in blood and pathological alterations comparable to the changes in type II diabetes mellitus

2016 ◽  
Vol 35 (8) ◽  
pp. 893-901 ◽  
Author(s):  
KK Vattam ◽  
HRB Raghavendran ◽  
MR Murali ◽  
H Savatey ◽  
T Kamarul
Keyword(s):  
Diabetes Mellitus ◽  
Type Ii Diabetes ◽  
Serum Insulin ◽  
Histological Section ◽  
Serum Levels ◽  
Type Ii Diabetes Mellitus ◽  
Type Ii ◽  
Sprague Dawley ◽  
Inflammatory Infiltration ◽  
Insulin Levels

Background:In the present study, thirty six male Sprague Dawley rats were randomly divided into six groups and were injected with varying doses of alloxan (Ax) and nicotinamide (NA). The serum levels of glucose, insulin, and adiponectin were measured weekly up to 4 weeks.Results:Elevated levels of glucose were observed in all groups on days 7, 14, 21, and 28, except in groups a and f (control). The serum insulin levels were significantly elevated in groups b and c on day 7, when compared with that in group f, whereas a decrease in the serum insulin levels was observed in groups d and e on days 21 and 28. The adiponectin levels showed inconsistencies on days 7 and 14. However, significant decrease in the adiponectin levels was observed on days 21 and 28. Histological section of the pancreas showed mild (group a), moderate (group b) to severe (groups c, d, and e) degenerative changes. Concomitant fatty changes in the liver and inflammatory infiltration of the kidney were markedly observed in all the treated groups, when compared to control.Conclusion:These results suggested that the use of selective combination of Ax120 + NA50 injection demonstrated type II diabetes mellitus in rats.

Obesity, Type II diabetes and the β2 adrenoceptor gene Gln27Glu polymorphism in the Tongan population

2003 ◽  
Vol 104 (3) ◽  
pp. 211-215 ◽  
Author(s):  
Natalia L. DUARTE ◽  
Stephen COLAGIURI ◽  
Taniela PALU ◽  
Xing L. WANG ◽  
David E.L. WILCKEN
Keyword(s):  
Glucose Metabolism ◽  
Type Ii Diabetes ◽  
Serum Insulin ◽  
Fasting Blood Glucose ◽  
Fat Free Mass ◽  
Type Ii ◽  
Genotype Frequencies ◽  
Gln27glu Polymorphism ◽  
High Prevalence ◽  
Prevalence Of Obesity

As there is a high prevalence of obesity in Tonga, we aimed to determine the distribution of the β2 adrenoceptor gene Gln27Glu polymorphism and to assess its relevance to obesity and to Type II diabetes, known to be prevalent in that population. A random sample of 1022 individuals from Tonga were genotyped for the Gln27Glu polymorphism in the β2 adrenoceptor gene. To assess the prevalence of obesity we measured body-mass index (BMI), fat-free mass, percentage fat and waist-to-hip ratio (WHR). To assess glucose metabolism we measured HbA1c, fasting blood glucose, fasting serum insulin, and 1- and 2-h glucose; we also measured serum lipid and creatinine levels. We found that 84% of the Tongan men and 93% of the women were overweight or obese (BMI⩾25kg/m2) and 15.1% had Type II diabetes. Genotype frequencies among the 1022 Tongans were: Gln/Gln 90.3% and Gln/Glu 9.6%; we found one Glu/Glu homozygote. The mean BMI (±S.D.) for men was not significantly different for those who were homozygous (30.2±5.4kg/m2) or heterozygous (30.1±5.5kg/m2) for the Gln allele; this was also true for women (33.7±6.2kg/m2 for homozygous and 34.0±5.6kg/m2 for heterozygous). The Glu allele was not associated with other measures of obesity or abnormal glucose metabolism in this generally overweight population. There is a unique frequency of the Gln/Glu β2 adrenoceptor polymorphism among Tongans. We found no association of the polymorphism with obesity measures or Type II diabetes-related variables in the Tongan population among whom we documented a high prevalence of obesity and Type II diabetes and a low frequency of the Glu allele.

scholarly journals Antidiabetic Action of Alfalfa (Medicago sativa) Leaves Powder on Type II Diabetic Patients

2019 ◽  
Vol 9 (1) ◽  
pp. 23-25
Author(s):  
Burhan A. Salih ◽  
Kokaz O. Azeez
Keyword(s):  
Medicago Sativa ◽  
Type Ii Diabetes ◽  
Serum Insulin ◽  
Type Ii Diabetes Mellitus ◽  
Diabetic Control ◽  
Standard Test ◽  
Diabetic Subject ◽  
Diabetic Patients ◽  
Type Ii ◽  
Healthy Control

Type II diabetes is a common metabolic disorder that is specified by hyperglycemia resulting from defects in insulin action. Alfalfa (Medicago sativa) is a medicinal plant (leaves, flower, and seeds) used traditionally as antidiabetic. This study is designed to investigate the short-term antidiabetic action of alfalfa leaves powder in patients with Type II diabetes mellitus. 12 volunteers suffering from type II diabetes were undertaken besides 12 healthy individuals. The subjects were divided into four groups including healthy control, diabetic control, which received an only meal, and the third and fourth groups were healthy and diabetic subjects which received alfalfa leaves powder within the meal. A standard test meal was supplemented with 8 g of alfalfa. The results showed that alfalfa leaves significantly (P = 0.03) reduces blood sugar 2 h after meal from 344.4 mg/dl to 300.75 mg/dl in the diabetic subject, in addition to the elevation of serum insulin levels (P = 0.02) at 30 min and elevation further creased (P = 0.06) at 120 min. This finding suggested that alfalfa leaves could be applied as a therapy against Type II diabetes.

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