• Bulletin of the Korean Chemical Society
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• 제31권10호
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• pp.2877-2883
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• 2010

The folding kinetics of $WT^*$ ubiquitin variant with valine to alanine mutation at sequence position 26 (HubWA) was studied by stopped-flow fluorescence spectroscopy. While unfolding kinetics showed a single exponential phase, refolding reaction showed three exponential phases. The semi-logarithmic plot of urea concentration vs. rate constant for the first phase showed v-shape pattern while the second phase showed v-shape with roll-over effect at low urea concentration. The rate constant and the amplitude of the third phase were constant throughout the urea concentrations, suggesting that this phase represents parallel process due to the configurational isomerization. Interestingly, the first and second phases appeared to be coupled since the amplitude of the second phase increased at the expense of the amplitude of the first phase in increasing urea concentrations. This observation together with the roll-over effect in the second folding phase indicates the presence of intermediate state during the folding reaction of HubWA. Quantitative analysis of Hub-WA folding kinetics indicated that this intermediate state is on the folding pathway. Folding kinetics measurement of a mutant HubWA with hydrophobic core residue mutation, Val to Ala at residue position 17, suggested that the intermediate state has significant amount of native interactions, supporting the interpretation that the intermediate is on the folding pathway. It is considered that HubWA is a useful model protein to study the contribution of residues to protein folding process using folding kinetics measurements in conjunction with protein engineering.

• Parasites, Hosts and Diseases
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• 제60권4호
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• pp.273-279
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• 2022

Laelapinae mites are involved in transmission of microbial diseases between wildlife and humans, with an impact on public health. In this study, 5 mite members in the subfamily Laelapinae (laelapin mites; LM) were morphologically identified by light microscopy, and the phylogenetic relationship of LM was analyzed in combination with the sequence information of part of the LM cytochrome oxidase subunit I (cox1) gene. The morphological identification revealed that 5 mites belonged to the genera Laelaps and Haemolaelaps, respectively. Sequence analysis showed that the ratio of nonsynonymous mutation rate to synonymous mutation rate of LM was less than 1, indicating that the LM cox1 gene had undergone purifying selection. Phylogenetic analysis showed that the Laelapinae is a monophyletic group. The genera Haemolaelaps and Hyperlaelaps did not separated into distinct clades but clustered together with species of the genus Laelaps. Our morphological and molecular analyses to describe the phylogenetic relationships among different genera and species of Laelapinae provide a reference for the improvement and revision of the LM taxonomy system.

• Tuberculosis and Respiratory Diseases
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• 제60권2호
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• pp.187-193
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• 2006

배 경 : 결핵균의 성장 속도가 늦은 이유가 mammalian cell이나 대장균에 비해 결핵균 AK의 매우 낮은 활성도에 의한 것이라는 추측으로부터 AK1과 유사한 촉매능을 나타내는 AKmt 돌연변이 유전자와 human muscle-type AK 합성 유전자(AK1)를 각각 Mycobacterium/E.coli 발현벡터에 재조합(pMVAKmtDM, pEMAK1)하여 성장 속도가 매우 느린 BCG에 형질전환함으로써 이들 단백질들의 촉매능에 의한 성장 속도 변화가 일어나는지를 확인하고자 하였다. 방 법 : Human AK1의 촉매 활성도와 유사하도록 결핵균 AK (AKmt)유전자의 ATPbd와 LID domain을 돌연변이하여 제조한 유전자(AKmtDM)와 human muscle-type adenylate kinase 합성 유전자(AK1)를 Mycobacterium/E.coli 발현벡터에 클로닝하여 재조합 BCG를 제조하였고, 이들 재조합 BCG와 BCG Pasteur $1173P_2$ (wild-type)를 7H9 액체배지에 접종하여 2-3 일 간격으로 $A_{600}$ 값을 측정하였다. 결 과 : 재조합 BCG의 성장 속도는 Wild-type BCG의 성장 속도에 비해 변화가 없었다. 결 론 : 결핵균 adenylate kinase의 정확한 기능은 알 수 없으나, adenylate kinase의 촉매 활성도의 증가는 BCG의 성장 속도에는 영향을 주지 않는 것으로 판단된다.

• 산업공학
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• 제14권3호
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• pp.227-235
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• 2001

There is a rapidly growing demand for wireless telecommunication. However, the number of usable channel is very limited. Therefore, the problem of channel assignment becomes more and more important to use channels as efficiently as possible. The objective of this paper is to develop an evolution program (EP) to find an efficient dynamic channel assignment method for minimum interference among the channels within reasonable time. The series of specific channel number is used as a representation of chromosome. The only changed chromosomes by crossover and mutation are evaluated in each generation to save computation time and memory for the progress of improved EP. We can easily differentiate the fitness value of each chromosome using proposed evaluation function. We also control the weighting factor of the mutation rate and the used number of elitist chromosomes for the speed of convergence to the optimal solution.

• Journal of Microbiology and Biotechnology
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• 제1권4호
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• pp.256-260
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• 1991

In B. subtilis, $\alpha$-amylase synthesis is regulated by amyR located directly on the upstream of amyE. Three different amyR alleles have been reported, amyR1, amyR2 and amyR3. Strains bearing the gra-10 mutation which confers derepression for catabolite repression has GlongrightarrowA transition mutation at ＋5 of amyR1. S1 nuclease mapping demonstrated that transcription initiated at 8 bases downstream from the -10 region of putative E$\sigma^{A}$ promoter P1 in amyR1 and gra-10. In amyR2, the major transcription initiatd at the same place and the minor, 10 bases downstream from -10 of P2. The transcript from P2 contributed approximately 15-20% of total amyE mRNA. S1 nuclease protection experiment indicated that amyE mRNA levels corresponded to the rate of synthesis assumed by specific activities of $\alpha$-amylase in culture supernatants, suggesting that $\alpha$-amylase synthesis is regulated at the level of transcription.n.

• 대한전기학회논문지:시스템및제어부문D
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• 제53권4호
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• pp.265-276
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• 2004

Genetic Algorithm(GA), that is shown stable performance to find an optimal solution, has been used as a method of solving large-scaled optimization problems with complex constraints in various applications. Since it takes so much time to execute a long computation process for iterative evolution and adaptation. In this paper, a hardware-based adaptive GA was proposed to reduce the serious computation time of the evolutionary process and to improve the accuracy of convergence to optimal solution. The proposed GA, based on steady-state model among continuos generation model, performs an adaptive mutation process with consideration of the evolution flow and the population diversity. The drawback of the GA, premature convergence, was solved by the proposed adaptation. The Performance improvement of convergence accuracy for some kinds of problem and condition reached to 5-100% with equivalent convergence speed to high-speed algorithm. The proposed adaptive GAP(Genetic Algorithm Processor) was implemented on FPGA device Xilinx XCV2000E of EHW board for face recognition.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.725-730
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• 2000

Genetic algorithms based on the theory of natural selection, have been applied to many different fields, and have proven to be relatively robust means to search for global optimum and handle discontinuous or even discrete data. Genetic algorithms are widely used for unconstrained optimization problems. However, their application to constrained optimization problems remains unsettled. The most prevalent technique for coping with infeasible solutions is to penalize a population member for constraint violation. But, the weighting of a penalty for a particular problem constraint is usually determined in the heuristic way. Therefore this paper proposes, the effective technique for handling constraints, the ranking penalty method and hybrid genetic algorithms. And this paper proposes dynamic mutation tate to maintain the diversity in population. The effectiveness of the proposed algorithm is tested on several test problems and results are discussed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2693-2695
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• 2001

In this paper, we present an adaptive image filter using genetic algorithm. The filter is robust to the characteristic variance of image and noise, by evolving the parameter and combination of image preprocessors properly. And we have adopted adaptive mutation strategy, which use different mutation rate for specific region of chromosome. The filter is implemented on FPGA board and controlled by host PC.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권8호
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• pp.2959-2973
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• 2021

In wireless sensor and actuator networks (WSANs), the network lifetime is an important criterion to measure the performance of the WSAN system. Generally, the network lifetime is mainly affected by the energy of sensors. However, the energy of sensors is limited, and the batteries of sensors cannot be replaced and charged. So, it is crucial to make energy consumption efficient. WSAN introduces multiple actuators that can be regarded as multiple collectors to gather data from their respective surrounding sensors. But how to deploy actuators to reduce the energy consumption of sensors and increase the manageability of the network is an important challenge. This research optimizes actuators deployment by a proposed probabilistic mutation multi-layer particle swarm optimization algorithm to maximize the coverage of actuators to sensors and reduce the energy consumption of sensors. Simulation results show that this method is effective for improving the coverage rate and reducing the energy consumption.

• Childhood Kidney Diseases
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• 제27권2호
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• pp.127-132
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• 2023

Cystinuria, a genetically inherited disorder, is a rare cause of kidney stones. It is characterized by impaired transport of cystine and amino acids in the proximal renal tubule and the small intestine. Most patients develop cystine stones throughout their lifetime. Recurrent renal stones need to be extracted by repeated urologic interventions. Treatment options of cystinuria for preventing stone recurrence are limited and poorly tolerated. In this study, we report a pediatric case of cystinuria with a heterozygous SLC3A1 mutation diagnosed by stone analysis, measurement of urine cystine excretion, and genetic analysis. There were recurrent renal stones despite repetitive shock wave lithotripsy and retrograde intrarenal surgery. However, the rate of stone formation seemed to be slower after D-penicillamine was added into adequate hydration and urinary alkalinization.