• Journal of Sensor Science and Technology
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• v.19 no.2
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• pp.142-148
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• 2010

We have compared and investigated the detection capabilities of antibody of immunoglobulin G(anti-IgG) immobilized by protein G and N-hydroxysuccinimide(NHS) at the end of the self-assembled monolayer(SAM). Surface plasmon resonance(SPR) sensor has been utilized to measure the interaction between biomolecules. After formation of the protein G and SAM, anti-IgG, bovine serum albumin(BSA) and IgG has been sequently injected. Through the reponse of the SPR, we can conclude that the protein G immobilized anti-IgG better than the SAM. In addition, IgG detection capability of the anti-IgG immobilized by the protein G showed better performance compared with that immobilized by the SAM.

• YAKHAK HOEJI
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• v.36 no.1
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• pp.66-72
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• 1992

In order to test relationships between hepatotoxicity and transmethylation, activities of protein methylases and SAM (S-adenosyl-L-methionine)-synthetase were examined in liver tissues of rats treated with $CCl_4$. Also the concentrations of SAM and SAH were measured by HPLC in rat liver. The results are as follows. (1). Activities of protein methylases were not significantly changed in 24 hours after $CCl_4$ treatment. However, in 48 hours, activities of protein methylases were significantly increased in comparison with that of control. (2). Activity of SAM-synthetase was increased steadily in the time course after $CCl_4$ treatment. (3). S-adenosyl-L-methionine concentration of liver tissues in $CCl_4$-treated group was elevated in 24 hours, and then declined thereafter. But the SAH concentration was slightly decreased in the time course after $CCl_4$ treatment. These results indicate that SAM was very actively used in transmethylation reactions of $CCl_4$ damaged rat liver, suggesting the strong relationships between hepatotoxicity and transmethylation phenomena.

• YAKHAK HOEJI
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• v.36 no.5
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• pp.460-468
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• 1992

Several bichemical parameters related to free radicals were estimated in senile-prone (P) and resistant(R) strains of male senescence-accelerated mice(SAM) at 2, 5 and 11 months of age. The superoxide generation was increased with age in SAM-R/1 and SAM-P/2. Compared to SAM-R/1, more generation of superoxide was significantly noted in the SAM-P/2 liver. The activities of Cu/Zn-superoxide dismutase and catalase were decreased during aging and these activities in SAM-P/2 were significantly lower than in SAM-R/l liver. The activities of glutathione S-transferase were varied with aging, whereas SAM-P/2 showed lower levels compared to SAM-R/l. The gradual decreases of glutathione, protein bound-SH and nonprotein bound-SH contents were noted with increasing age. SAM-P/2 liver contained lesser amounts of glutathione and nonprotein bound-SH compared to SAM-R. In conclusion, superoxide generation was increased whereas the antioxidant enzyme activities were decreased during aging in SAM-R/1. In addition, SAM-P/2 strain showed more superoxide generation and less antioxidant enzyme activities than SAM-R/1 in the liver, thus we assume that these factors might accelerate the senescence of SAM-P/2 strain.

• BMB Reports
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• v.43 no.5
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• pp.355-362
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• 2010

The sterile alpha motif (SAM) is a putative protein interaction domain involved in a wide variety of biological processes. Here we report the identification and characterization of a novel gene, SAMD4B, which encodes a putative protein of 694 amino acids with a SAM domain. Northern blot and RT-PCR analysis showed that SAMD4B is widely expressed in human embryonic and adult tissues. Transcriptional activity assays show SAMD4B suppresses transcriptional activity of L8G5-luciferase. Over-expression of SAMD4B in mammalian cells inhibited the transcriptional activities of activator protein-1 (AP-1), p53 and p21, and the inhibitory effects can be relieved by siRNA. Deletion analysis indicates that the SAM domain is the main region for transcriptional suppression. The results suggest that SAMD4B is a widely expressed gene involved in AP-1-, p53- and p21-mediated transcriptional signaling activity.

• Journal of Sensor Science and Technology
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• v.16 no.2
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• pp.104-109
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• 2007

In this paper, we have fabricated on extended-gate field effect transistor (EGFET)-type protein sensor for the application to a CRP detection. We used the self-assembled monolayer (SAM) to adhere or entrap biomolecules, namely CRP antibodies. The experimental result shows that the proposed SAM is well immobilized on the gold gate surface. So the drain current was varied by antigen-antibody interactions on the gate surface because of the CRP charge. Experimental results related to the formation of SAM, antibody, antigen were obtained by measuring the electrical characteristics of the EGFET device.

• Journal of Microbiology and Biotechnology
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• v.16 no.6
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• pp.927-932
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• 2006

S-Adenosylmethionine (SAM) is a ubiquitous biomolecule serving mainly as a methyl donor. Our recent studies revealed that SAM controls antibiotic production in Streptomyces. In this study, the functional mode of SAM was studied in S. coelicolor and S. antibioticus ATCC11891, employing S-adenosylhomocysteine (SAH), a methylation reaction product of SAM. Actinorhodin biosynthesis did not require SAM as a methyl donor, whereas SAH enhanced the actinorhodin biosynthesis up to the level comparable to SAM, and the most effective concentration of SAH was higher than that of SAM. In the case of oleandomycin that requires SAM for its biosynthesis, both SAM and SAH at the concentration as low as 100 mM showed comparable efficacy in enhancing the production; SAM at 1 mM concentration additionally stimulated to give a 5-fold enhancement of oleandomycin production. In vitro autophosphorylation of protein kinase AfsK was found to be activated by both SAM and SAH, as well as other structurally related compounds. Our studies demonstrate that SAM regulates antibiotic biosynthesis in a mode independent of its role as a methyl donor and suggest that SAM acts directly as an intracellular signaling molecule for Streptomyces.

• Journal of Life Science
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• v.21 no.9
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• pp.1226-1233
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• 2011

In neurons, kinesin is the molecular motor that transport cargos along microtubules. KIF5s (alias kinesin-I), are heterotetrameric motor conveying cargos, but the mechanism as to how they recognize and bind to a specific cargos has not yet been completely elucidated. To identify the interaction proteins for KIF5C, yeast two-hybrid screening was performed, and specific interaction with the $\underline{S}$am68-$\underline{l}$ike $\underline{m}$ammalian protein $\underline{2}$ (SLM-2), a member of the $\underline{s}$ignal $\underline{t}$ransducers and $\underline{a}$ctivators of $\underline{R}$NA (STAR) family of RNA processing proteins, was found. SLM-2 bound to the carboxyl (C)-terminal region of KIF5C and to other KIF5 members. The C-terminal domain of Sam68, SLM-1, SLM-2 was essential for interaction with KIF5C in the yeast two-hybrid assay. In addition, glutathione S-transferase (GST) pull-downs showed that SAM68, SLM-1, and SLM-2 specifically interacted to Kinesin-I complex. An antibody to SAM68 specifically co-immunoprecipitated SAM68 associated with KIF5s and coprecipitated with a specific set of mRNA. These results suggest that Kinesin-I motor protein transports RNA-associated protein complex in cells.

• Nutrition Research and Practice
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• v.14 no.4
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• pp.309-321
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• 2020

BACKGROUND/OBJECTIVES: The present study aimed to evaluate the effects of folic acid supplementation in high-fructose-induced hepatic steatosis and clarify the underlying mechanism of folic acid supplementation. MATERIALS/METHODS: Male SD rats were fed control, 64% high-fructose diet, or 64% high-fructose diet with folic acid for eight weeks. Plasma glutamate-pyruvate transaminase, glutamate-oxaloacetate transaminase, lipid profiles, hepatic lipid content, S-adenosylmethionine (SAM), and S-adenosylhomocysteine (SAH) were measured. RESULTS: The HF diet significantly increased hepatic total lipid and triglyceride (TG) and decreased hepatic SAM, SAH, and SAM:SAH ratio. In rats fed a high fructose diet, folic acid supplementation significantly reduced hepatic TG, increased hepatic SAM, and alleviated hepatic steatosis. Moreover, folic acid supplementation in rats fed high fructose enhanced the levels of phosphorylated AMP-activated protein kinase (AMPK) and liver kinase B (LKB1) and inhibited phosphorylation of acetyl coenzyme A carboxylase (ACC) in the liver. CONCLUSIONS: These results suggest that the protective effect of folic acid supplementation in rats fed high fructose may include the activation of LKB1/AMPK/ACC and increased SAM in the liver, which inhibit hepatic lipogenesis, thus ameliorating hepatic steatosis. The present study may provide evidence for the beneficial effects of folic acid supplementation in the treatment of non-alcoholic fatty liver disease.

• Journal of Sensor Science and Technology
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• v.19 no.6
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• pp.456-461
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• 2010

The detection of C-reactive protein(CRP) using self-assembled monolayer(SAM) was investigated by a portable surface plasmon resonance(SPR) sensor system. The CRP is a biomarker for the possible cardiovascular disease. The SAM was formed on gold(Au) surface to anchor the monoclonal antibody of CRP(anti-CRP) for detection of CRP. Sequence injection of the anti-CRP and bovine serum albumin(BSA) into the sensor system has been carried out immobilize the antibody and to prevent non-specific binding. The portable SPR system has two flow channels: one for the sample measurements and the other for the reference. The output SPR signal was increased with the injection of the anti-CRP, BSA and CRP due to binding of the proteins on the sensor chip. The valid output SPR signals was linearly related to the critical range of the CRP concentration. The experimental results showed the feasibility of the portable SPR system with newly developed SAM to diagnose a risk of the future cardiovascular events.

• Journal of Nutrition and Health
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• v.40 no.2
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• pp.130-137
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• 2007

Myelin basic protein (MBP), a major structural protein of the myelin, is thought to be important for the maintenance of myelin in the central nervous system (CNS). We investigated the effect of maternal folic acid nutritional status on the folate level and the synthesis of MBP in the offspring. In order to test this hypothesis, female Sprague-Dawley rats were fed either folic acid sufficient (8 mg/kg diet) or deficient (0 mg/kg diet) diet from 2 wks prior to the mating throughout the entire pregnancy, lactation and weaning period. We examined plasma folate level by the radioimmunoassay and homocysteine level by HPLC, respectively. The MBP expression was measured by the western blot analysis. The maternal folic acid deficiency decreased plasma folate level with a concomitant increase in plasma homocysteine level in their offspring. The maternal folic acid deficiency decreased hepatic levels of SAM and SAM/SAH ratio with a concomitant increase in hepatic levels of SAH and the MBP expression of spinal cord in their offspring at 7 wks of age. These results suggest that maternal folic acid nutritional status affect plasma folate and homocysteine level in their offspring. Moreover, the maternal folic acid deficiency mi호t inhibit the MBP expression of the spinal cord and disrupt many other vital CNS reactions in their offspring.