The crystal structure of 0.19 alpha-amylase inhibitor (0.19 AI) from wheat kernel was determined by the multiple-isomorphous replacement method coupled with density modification and noncrystallographic symmetry averaging and then refined by simulated annealing using diffraction data to 2.06 A resolution (R = 18.7%, free R = 22.3%). The asymmetric unit has four molecules of 0.19 AI, each comprised of 124 amino acid residues. Electron density for residues 1-4 and 69-77 is absent in all subunits, probably because of the intrinsic flexibility of these segments. Each subunit has four major alpha-helices and one one-turn helix which are arranged in the up-and-down manner, maintaining the favorable packing modes of the alpha-helices. 0.19 AI, however, has two short antiparallel beta-strands. All 10 cysteine residues in 0.19 AI form disulfide bonds (C6-C52, C20-C41, C28-C83, C42-C99, and C54-C115), consistent with the assignments made biochemically for 0.28 AI from wheat kernel and by NMR analysis of the bifunctional alpha-amylase/trypsin inhibitor from ragi seeds (RBI). The disulfide bond patterns in these AIs are similar to those in the hydrophobic protein from soybean (HPS), which lack only the bond corresponding to C28-C83 in 0.19 AI. Extensive interactions occurred between particular pairs of 0.19 AI subunits, mainly involving hydrophobic residues. Comparisons of the structures of 0.19 AI, RBI, and HPS showed that the arrangements of the major alpha-helices are similar but the conformations of the remaining residues differ markedly. The present X-ray analysis for 0.19 AI and the NMR analysis for RBI suggest that all the AIs in this family have a common fold. The alpha-amylase binding site is discussed on the basis of the tertiary and quaternary structures of 0.19 AI together with biochemical and spectroscopic data for AIs.

A reduction of visceral fat is important for improvement of metabolic risk. This study was designed to compare the effects of a web-based program alone or together with measurement and self-awareness of accumulated visceral fat in Japanese workers. A new noninvasive device to measure visceral fat accumulation was introduced, and efficacy on weight-loss and improvement of healthy behaviors were examined. This study was conducted according to Helsinki declaration and approved by the ethical committee of Japan Hospital Organization, National Kyoto Hospital. Two-hundred and sixteen overweight and obese males with BMI of more than 23 participated from 8 healthcare offices of 3 Japanese private companies. Subjects were randomly allocated into control group, Web-based weight-loss program (Web), or Web + Visceral fat measurement group (Web + VFA). Eighty-one percent of participants completed the study. Reductions of body weight, waist circumference, and BMI were the largest in Web + VFA group, and the differences between groups were significant by ANOVA. Improvements of healthy behaviors were the largest in Web + VFA group, and the differences of healthy eating improvement scores between Web + VFA and control groups were significant. Our findings suggest that measurement and awareness of visceral fat are effective in weight reduction in overweight and obese males in the workplace.

Background and Objectives. The increased prevalence of metabolic syndrome necessitates the establishment of tools for evaluating dietary factors associated with visceral fat accumulation and preventing visceral fat obesity. Here, we aimed to develop a dietary factor assessment tool for evaluating visceral fat accumulation. Methods. We conducted a dietary habit questionnaire survey and visceral fat measurement by bioelectrical impedance analysis in 11,438 adults (Survey 1) and a dietary habit questionnaire survey and dietary assessment based on 3-day meal records in 579 adults (Survey 2). Dietary habit factors were identified by factor analysis with varimax rotation, and their relationship with visceral fat accumulation and major nutrients were analyzed. Results. Factor analysis of the dietary habit questionnaire revealed the following five main dietary factors: “Appetite (15 questions),” “Healthy food choice (5 questions),” “Sedentary behavior (6 questions),” “Calorie restriction (5 questions),” and “Irregular mealtime (4 questions).” “Appetite” correlated positively with visceral fat accumulation and energy intake mainly from carbohydrate. “Healthy food choice” correlated negatively with visceral fat accumulation and positively with the protein/fat ratio, dietary fiber/carbohydrate ratio, and N-3 fatty acid/fat ratio. Dietary guidance to modify excess energy intake and increase nutritional balance might be effective toward preventing visceral fat accumulation. Conclusions. The dietary factor assessment tool developed in this study can be used to diagnose problems related to dietary habits and provide guidance for dietary modifications aimed at preventing visceral fat accumulation.

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