Tofu Research Today is a free monthly online journal that collates and summarizes the latest research about Tofu, including details on soy protein, soya bean, bean curd, health benefits, risks.

Antimicrobial activity of gamma-thionin-like soybean SE60 in E. coli and tobacco plants.

Choi Y, Choi YD, Lee JS

School of Biological Sciences, Seoul National University, Seoul 151-747, Republic of Korea. yhc@snu.ac.kr

The SE60, a low molecular weight, sulfur-rich protein in soybean, is known to be homologous to wheat gamma-purothionin. To elucidate the functional role of SE60, we expressed SE60 cDNA in Escherichia coli and in tobacco plants. A single protein band was detected by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) after anti-FLAG affinity purification of the protein from transformed E. coli. While the control E. coli cells harboring pFLAG-1 showed standard growth with Isopropyl beta-d-1-thiogalactopyranoside (IPTG) induction, E. coli cells expressing the SE60 fusion protein did not grow at all, suggesting that SE60 has toxic effects on E. coli growth. Genomic integration and the expression of transgene in the transgenic tobacco plants were confirmed by Southern and Northern blot analysis, respectively. The transgenic plants demonstrated enhanced resistance against the pathogen Pseudomonas syringae. Taken together, these results strongly suggest that SE60 has antimicrobial activity and play a role in the defense mechanism in soybean plants.

Published 3 September 2008 in Biochem Biophys Res Commun, 375(2): 230-4.
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Articles on Tofu published 4 August 2008:

Isoflavones in children and adults consuming soy.   Arch Biochem Biophys, 476(2): 161-70.

Soy and their isoflavones (IFLs) are believed to protect against breast cancer, particularly when exposure occurs during childhood. Little is known about the bioavailability of IFLs in children and how this is affected by oral antibiotics (OABX). We measured IFLs by LC/MS and found that the urinary IFL excretion rate (UIER) reflects circulating IFLs accurately when area-under-curve (AUC) and identical time intervals are used (r=0.93; p<0.001). UIER in children and adults was determined when ... [Abstract] [Full-text]

Articles on Tofu published 2 July 2008:

Soy intake and breast cancer risk in Singapore Chinese Health Study.   Br J Cancer, 99(1): 196-200.

We investigated the effects of soy isoflavone intake on breast cancer in a prospective study of 35,303 Singapore Chinese women enrolled during April 1993 to December 1998 in the Singapore Chinese Health Study. At recruitment, each subject was personally administered a validated semiquantitative food frequency questionnaire covering 165 food and beverage items. As of December 31,2005, 629 had developed breast cancer following an accumulation of 338,242 person-years. Using Cox regression and ... [Abstract] [Full-text]

Articles on Tofu published 30 June 2008:

Strong negative association between intake of tofu and anemia among Chinese adults in Jiangsu, China.   J Am Diet Assoc, 108(7): 1146-53.

BACKGROUND: Anemia is prevalent in China. Tofu made from soybean is a popular food. Soybean is shown to have an affect on iron status. No study has examined the relation between tofu and iron status. OBJECTIVE: To investigate the association between tofu intake and anemia among Chinese adults. DESIGN: A cross-sectional household survey of 2,849 men and women aged 20 years and older (mean age 47.0+/-14.5 years), from a nationally representative random sample in Jiangsu province undertaken in ... [Abstract] [Full-text]

Articles on Tofu published 24 June 2008:

Somatotropic responses to soy protein alone and as part of a meal.   Eur J Endocrinol, 159(1): 15-8.

CONTEXT: GH is an important regulator of growth and body composition. We previously showed that GH release can be promoted by oral ingestion of soy protein; it is not known, however, whether these somatotropic effects of soy protein are also present when soy protein is ingested as part of a complete meal. OBJECTIVE/DESIGN: We compared the effects of oral ingestion of soy protein alone with the effects of a meal containing the same amount of soy protein on GH secretion in six healthy women (body ... [Abstract] [Full-text]

Articles on Tofu published 9 June 2008:

Soy consumption is not a risk factor for peanut sensitization.   J Allergy Clin Immunol, 121(6): 1455-9.

BACKGROUND: A recent cohort study suggested that intake of soy milk or soy formula was associated with peanut allergy. If this finding is confirmed, it suggests an avenue for modification of diet as a peanut allergy prevention strategy. OBJECTIVE: To investigate the relationship between soy consumption and peanut sensitization in a prospective cohort study of children. METHODS: A total of 620 babies with a family history of allergic disease were recruited. Dietary information was obtained from ... [Abstract] [Full-text]

Articles on Tofu published 16 May 2008:

Soy consumption reduces the risk of non-small-cell lung cancers with epidermal growth factor receptor mutations among Japanese.   Cancer Sci, 99(6): 1202-8.

Epidermal growth factor receptor (EGFR) mutations play substantial roles in genesis and proliferation of non-small-cell lung cancers (NSCLCs). We recently found that reproductive factors have a substantial impact on risk of development of NSCLCs featuring such EGFR mutations. Therefore, we explored the influence of dietary habits on NSCLC risk with reference to the EGFR mutational status. We conducted a case-control study using 353 patients with NSCLCs (122 EGFR mutated and 231 EGFR wild-type) ... [Abstract] [Full-text]

Articles on Tofu published 5 May 2008:

The role of early life genistein exposures in modifying breast cancer risk.   Br J Cancer, 98(9): 1485-93.

Review of the existing literature suggests that consumption of soy foods or an exposure to a soy isoflavone genistein during childhood and adolescence in women, and before puberty onset in animals, reduces later mammary cancer risk. In animal studies, an exposure that is limited to the fetal period or adult life does not appear to have the same protective effect. A meta-analysis of human studies indicates a modest reduction in pre- and postmenopausal risk when dietary intakes are assessed ... [Abstract] [Full-text]

Articles on Tofu published 2 May 2008:

Use of soy protein-based formulas in infant feeding.   Pediatrics, 121(5): 1062-8.

Soy protein-based formulas have been available for almost 100 years. Since the first use of soy formula as a milk substitute for an infant unable to tolerate a cow milk protein-based formula, the formulation has changed to the current soy protein isolate. Despite very limited indications for its use, soy protein-based formulas in the United States may account for nearly 25% of the formula market. This report reviews the limited indications and contraindications of soy formulas. It will also ... [Abstract] [Full-text]

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