• BMB Reports
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• 제42권2호
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• pp.113-118
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• 2009

Despite the growing body of evidence suggesting a role for MsrA in antioxidant defense, little is currently known regarding the function of MsrB in cellular protection against oxidative stress. In this study, we overexpressed the mammalian MsrB and MsrA genes in Saccharomyces cerevisiae and assessed their subcellular localization and antioxidant functions. We found that the mitochondrial MsrB3 protein (MsrB3B) was localized to the cytosol, but not to the mitochondria, of the yeast cells. The mitochondrial MsrB2 protein was detected in the mitochondria and, to a lesser extent, the cytosol of the yeast cells. In this study, we report the first evidence that MsrB3 overexpression in yeast cells protected them against $H_2O_2$-mediated cell death. Additionally, MsrB2 overexpression also provided yeast cells with resistance to oxidative stress, as did MsrA overexpression. Our results show that mammalian MsrB and MsrA proteins perform crucial functions in protection against oxidative stress in lower eukaryotic yeast cells.

• BMB Reports
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• 제42권9호
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• pp.580-585
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• 2009

Dimethyl sulfoxide (DMSO) is widely used in chemistry and biology as a solvent and as a cryoprotectant. It is also used as a pharmaceutical agent for the treatment of interstitial cystitis and rheumatoid arthritis. Previous reports described DMSO as being reduced by methionine-S-sulfoxide reductase (MsrA). However, little is known about the DMSO reduction capability of methionine-R-sulfoxide reductase (MsrB) or its effect on the catalysis of methionine sulfoxide reduction. We show that mammalian MsrB2 and MsrB3 were unable to reduce DMSO. This compound inhibited MsrB2 activity but did not inhibit MsrB3 activity. We further determined that DMSO functions as an inhibitor of MsrA and MsrB2 in the reduction of methionine sulfoxides via different inhibition mechanisms. DMSO competitively inhibited MsrA activity but acted as a non-competitive inhibitor of MsrB2 activity. Our study also demonstrated that DMSO inhibits in vivo methionine sulfoxide reduction in yeast and mammalian cells.

• Weed & Turfgrass Science
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• 제2권2호
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• pp.159-163
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• 2013

본 논문은 가뭄저항성 유전자를 도입한 GM벼(CaMsrB2-8)를 모품종 일미와 비교하여 잡초화 가능성의 여부를 판단하고자 실시하였다. GM벼(CaMsrB2-8)의 생육특성과 발아율 실험 결과 모품종 일미와 큰 차이를 보이지 않았고, 모든 종자는 6일 후 발아하였다. GM벼(CaMsrB2-8)와 일미의 수발아성 실험을 $23{\pm}2^{\circ}C$ 온실에서 충분한 물을 분무하여 40일간 진행한 결과 수발아는 발생하지 않았다. 라튜닝 후 GM벼(CaMsrB2-8)와 일미의 지상부 생장을 비교한 결과 7-14일 동안 일미보다 GM벼(CaMsrB2-8)의 성장이 빠른 것처럼 보였으나 그 이후 14-21일 동안에는 두 개체가 비슷한 성장세를 보였다. GM벼(CaMsrB2-8)와 일미의 탈립율은 두 개체가 비슷하였으며 등숙율 또한 90%이상으로 비슷한 수준을 보였다. 종자의 월동성을 조사한 결과 발아율 0%로 자연상태에서 월동 후 발아 가능성은 없을 것으로 보인다. 따라서 본 연구를 토대로 GM벼(CaMsrB2-8)에 도입된 내건성유전자는 벼의 농업적 특성을 변화시키지 않는 것으로 판단되며 따라서 GM벼(CaMsrB2-8) 재배 시 잡초화 되지는 않을 것으로 생각된다.

• Journal of Microbiology and Biotechnology
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• 제18권1호
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• pp.59-62
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• 2008

The peptide methionine sulfoxide reductases (Msrs) are enzymes that catalyze the reduction of methionine sulfoxide back to methionine. Because of two enantiomers of methionine sulfoxide (S and R forms), this reduction reaction is carried out by two structurally unrelated classes of enzymes, MsrA (E.C. 1.8.4.11) and MsrB (E.C. 1.8.4.12). Whereas MsrA has been well characterized structurally and functionally, little information on MsrB is available. The recombinant MsrB from Bacillus subtilis has been purified and crystallized by the hanging-drop vapor-diffusion method, and the functional and structural features of MsrB have been elucidated. The crystals belong to the trigonal space group P3, with unit-cell parameters a=b=136.096, $c=61.918{\AA}$, and diffracted to $2.5{\AA}$ resolution using a synchrotron-radiation source at Pohang Light Source. The asymmetric unit contains six subunits of MsrB with a crystal volume per protein mass $(V_M)\;of\;3.37{\AA}^3\;Da^{-1}$ and a solvent content of 63.5%.

• Progress in Superconductivity
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• 제9권1호
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• pp.45-49
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• 2007

We have investigated the optimum combination of the environmental noise condition and type of SQUID pickup coil in order to obtain maximum signal-to-noise ratio (SNR). The measurement probe consists of 1st order gradiometer with pickup coils of 100 mm, 70 mm, and 50 mm baseline length, a 2nd order gradiometer with 50 mm baseline, and a magnetometer. The pickup coils are fabricated by winding Nb wire on a bobbin with 200 mm diameter. Noise and heart signal of a healthy male were measured by various SQUID sensors with different types of pickup coils in various magnetically shielded rooms (MSR), and compared to each other. The shielding factors were found to be 43 dB, 35 dB and 25 dB at 0.1 Hz for MSR-AS, MSR-BS, MSR-CS, respectively. White noises were $3.5\;fT/Hz^{1/2}$, $4.5\;fT/Hz^{1/2}$ and $3\;fT/Hz^{1/2}$ for the 1st order gradiometers, the 2nd order gradiometers, and magnetometer for all MSRs. SNR of the magnetometer was up to 56 dB in MSR-AS, while the 1st order axial gradiometer with 70 mm baseline length was up to 54 dB in MSR-BS. The 2nd order axial gradiometer with 50 mm baseline length of pickup coil was found to be up to 40 dB in MSR-CS.

• BMB Reports
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• 제44권4호
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• pp.256-261
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• 2011

PEP-1 peptide has been used for transduction of native protein into mammalian cells. This work describes the findings that the fusion of PEP-1 to target proteins led to protein truncation likely in a non-protein-specific manner. Approximately 75% of PEP-1-MsrA fusion protein was truncated in the N-terminal region of MsrA between Lys-27 and Val-28 during expression in Escherichia coli and purification. This large protein truncation was also observed in another PEP-1 fused protein, PEP-1-MsrB2, in the N-terminal region of MsrB2. The full-length PEP-1-MsrA protein was rapidly transduced into keratinocyte cells within 15 min. The transduced PEP-1-MsrA was functionally active and could protect skin cells against oxidative stress- and ultraviolet radiation-induced cell death. Collectively, our data demonstrated the protective roles of MsrA in skin cells and, moreover, may raise a concern of protein truncation caused by fusion of PEP-1 about the general use of this peptide for protein transduction.

• KSBB Journal
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• 제16권4호
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• pp.415-419
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• 2001

Bacillus subtilis WB700에서 P43 프로모터를 사용하여 staphylokinase를 생산하기 위하여 배지 최적화 및 회분식 배양과 유가식 배양 두가지 시스템을 비교하였다. 여러 가지 질소윈 중에서는 tryptone이 가장 좋은 질소원 이었으며, MSR 배지를 사용한 경우 tryptone 15 g/L일 경우에 최적조건임을 알아내었다. MSR 배지에시 포도당을 제한 기질로 사용할 경우는 5 g/L일 때가 SAK의 발현에 최적 조건이었다. MSR 배지를 기본으로 이용하여 포도당 공급을 조절함으로서 발효조 내의 DO를 30%로 유지한 결과 오히려 MSR 배지를 이용하여 회분식 발효를 한 경우보다 좋지 못한 결과를 얻었으며, 이는 B. subtilis 숙주의 영양요구적 특이성과 P43 promoter의 stress 발생시 주 발현되는 특성 등에 기인한 것이라고 사료된다. MSR 배지를 이용하여 회분식 발효를 하였을 때 SAK 활성은 2880 unit이었고, 이때 배지 내로 분비된 SAK 농도는 455 mg/L이었다.

• Current Research on Agriculture and Life Sciences
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• 제31권2호
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• pp.124-130
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• 2013

환경변화 중요성과 유전적 안전성은 최근에 증가추세의 형질전환 작물에 인식되고 있다. 본 실험은 건조저항성 형질전환체 작물의 유전적인 안전성과 환경변이에 따른 농업적인 특성을 분석하였다. 내건성 형질전환체인 CaMsrB2-8, 23과 모품종인 '일미' 및 일반품종을 대조구로 GM필드에서 작물학적 생육특성을 조사하였다. 농업적인 생육 특성에서 CaMsrB2-8, 23 계통은 모품종인 '일미'와 년차간, 지역별 평균으로 표현형은 유사하였다. 수량에서 년도별, 지역별 차이는 있지만 통계적인 유의성은 없었다. 현미의 미립특성에서 CaMsrB2-8, 23은 모품종인 '일미'와 차이를 보이지 않았다. 현미의 화학적 성분 분석에서 CaMsrB2-2 계통의 전분과 단백질함량은 모품종인 '일미'보다 일반품종인 '일품' 화학적 성분함량이 유사하였다. 본 실험결과에서 내건성 형질전환체인 CaMsrB2-8, 23는 GM 작물의 후대에서도 유전적인 안전성과 함께 수행될 수 있을 것으로 사료된다.

• BMB Reports
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• 제43권9호
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• pp.622-628
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• 2010

Dimethyl sulfoxide (DMSO) can be reduced to dimethyl sulfide by MsrA, which stereospecifically catalyzes the reduction of methionine-S-sulfoxide to methionine. Our previous study showed that DMSO can competitively inhibit methionine sulfoxide reduction ability of yeast and mammalian MsrA in both in vitro and in vivo, and also act as a non-competitive inhibitor for mammalian MsrB2, specific for the reduction of methionine-R-sulfoxide, with lower inhibition effects. The present study investigated the effects of DMSO on the physiological antioxidant functions of methionine sulfoxide reductases. DMSO elevated hydrogen peroxide-mediated Saccharomyces cerevisiae cell death, whereas it protected human SK-Hep1 cells against oxidative stress. DMSO reduced the protein-carbonyl content in yeast cells in normal conditions, but markedly increased protein-carbonyl accumulation under oxidative stress. Using Msr deletion mutant yeast cells, we demonstrated the DMSO's selective inhibition of the antioxidant function of MsrA in S. cerevisiae, resulting in an increase in oxidative stress-induced cytotoxicity.

• BMB Reports
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• 제44권10호
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• pp.669-673
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• 2011

Human methionine sulfoxide reductase B3A (hMsrB3A) is an endoplasmic reticulum (ER) reductase that catalyzes the stereospecific reduction of methionine-R-sulfoxide to methionine in proteins. In this work, we identified an antimicrobial peptide from hMsrB3A protein. The N-terminal ER-targeting signal peptide (amino acids 1-31) conferred an antimicrobial effect in Escherichia coli cells. Sequence and structural analyses showed that the overall positively charged ER signal peptide had an Argand Pro-rich region and a potential hydrophobic ${\alpha}$-helical segment that contains 4 cysteine residues. The potential ${\alpha}$-helical region was essential for the antimicrobial activity within E. coli cells. A synthetic peptide, comprised of 2-26 amino acids of the signal peptide, was effective at killing Gram-negative E. coli, Klebsiella pneumoniae, and Salmonella paratyphi, but had no bactericidal activity against Gram-positive Staphylococcus aureus.