• Macromolecular Research
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• v.17 no.4
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• pp.259-264
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• 2009

Chemical modification of magnetic nanoparticles(MNPs) with functional polymers has recently gained a great deal of attention because of the potential application of MNPs to in vivo and in vitro biotechnology. The potential use of MNPs as capturing agents and sensitive biosensors has been intensively investigated because MNPs exhibit good separation-capability and binding-specificity for biomolecules after suitable surface functionalization processes. In this work, we demonstrate an efficient method for the surface modification of MNPs, by combining surface-initiated polymerization and the subsequent conjugation of the biologically active molecules. The polymeric shells of non-biofouling poly(poly(ethylene glycol) methacrylate)(pPEGMA) were introduced onto the surface of MNPs by surface-initiated, atom transfer radical polymerization(SI-ATRP). With biotin as a model of biologically active compounds, the polymeric shells underwent successful post-functionalization via activation of the polymeric shells and bioconjugation of biotin. The resulting MNP hybrids showed a biospecific binding property for streptavidin and could be separated by magnet capture.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.4 no.1
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• pp.46-53
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• 2004

3-Methylcrotonyl-CoA carboxylase (MCC) is a biotin-dependent enzyme involved in leucine metabolism. We describe a patient with MCC deficiency who manifested with Reye syndrome-like illness with status epilepticus, metabolic acidosis, hypoglycemia, hyperammonemia, elevated liver enzymes and neurologic impairments after the viral gastroenteritis and then, has suffered from Lennox-Gastaut syndrome. Urinary organic acid analysis revealed increased excretion of 3-hydroxyisovaleric acid and 3-methylcrotonylglycine. This patient was managed with leucine restriction diet and supplementation of biotin and carnitine but was not so effective. He has suffered from neurologic sequelae such as Lennox-Gastaut syndrome, motor and cognitive impairement.

• Korean Journal of Microbiology
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• v.12 no.3
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• pp.115-130
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• 1974

Searches for the nutrition requirements of three strains of Brevibacterium ammoniagenes reported in the previous paper were carried out with an aim of achieving the striking accumulation of L-glutamic acid and the large multipication of cells. It was recognized that all three strains required both biotin and thiamine, together with amino acids such as histidine or cysteine, for their good growth and extracellular L-glutamic acid accumulation. The quantity of biotin required for remarkable growth of these microorganisms was quite different from that for the maximum production of L-glutamic acid. This result, however, did not apply in the case of thiamine. It was also confirmed that, of 18 amino acids, histidine and cysteine were the msot effective organic nitrogen sources, while the most available inorganic ammonium salt resulting in a large amount of L-glutamic acid-production and considerable cell gorwth was found to be only urea. Maximum accumulation of extracellular L-glutamic acid, more than 50%(w/w) of the initial sugar content, could be obtained from fermentation in the medium containing wheat-bran extract(Brev. ammoniagenes T-1 and Brev.ammoniagenes Y-2) or rice-bran extract(Brev. ammoniagenes YR-2), which confirmed us a possibility that these bacteria might be employed for industrial fermentation of L-glutamic acid.

• Bulletin of the Korean Chemical Society
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• v.29 no.2
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• pp.347-351
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• 2008

Acetyl-CoA carboxylase (ACC) is an excellent candidate for antibiotics drug target, which mediates malonyl-CoA synthesis from acetyl-CoA through acetylation process. It is also involved in the committed step of fatty acid synthesis which is essential for living organisms. We have determined the three dimensional structure of C terminal domain of HP0371, biotin-carboxyl carrier protein of H. pyroli, in solution state using heteronuclear multi-dimensional NMR spectroscopy. The structure of HP0371 shows a flatten b-sheet fold which is similar with that of E. coli. However, the sequence and structure of protruding thumb are different with that of E. coli and the thumb shows different basis of structural rigidity based on backbone dynamics data.

• BMB Reports
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• v.30 no.5
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• pp.308-314
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• 1997

We investigated biotinylation of nitrocellulose membrane for immuno-filtration capture assay. In order to enhance the efficiency of biotinylation, nitrocellulose membranes were pretreated with several chemicals for the purpose of suitable protein absorption through surface modification. As a signal generating enzyme, urease was used and the concentration of avidin was optimized for the efficient binding kinetics between urease-biotin in liquid phase and biotinylated membrane in solid phase. For effective biotinylation, bovine serum albumin-biotin complexes could be immobilized at a concentration of $370\;{\mu}g$/stick ($4.4\;cm^2$). Among tested chemicals, polylysine (0.25%) showed a significant effect in biotinylation. Polylysine is thought to enhance surface area by extending unbound residues into solution. Time of treatment over 30 min and higher molecular weight of polylysines (58,100 dalton) showed positive effect on the enhancement of biotinylation. The result from this study may be useful for developing a new biosensor and other biofunctional membranes for examining molecular recognition.

• The Korean Journal of Food And Nutrition
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• v.13 no.6
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• pp.558-562
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• 2000

A strain of non-sulfur photosynthetic bacteria possessing large amount of ubiquinone-10 in the cell mass, was isolated from waste water collected from the Nakdong River. It was identified as Rhodobacter sp. N-2 by a series of studies on its morphological. cultural and physiological characteristics. The organism appeared to got higher cell mass under circumstances of anaerobic growth conditions than under photosynthetic aerobic cultures. Biotin and thiamin and niacin could be used as good growth factors.

• KSBB Journal
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• v.6 no.3
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• pp.321-325
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• 1991

In thisstudy, effects of medium components on microbial production of L-phenylalanine by Corynebacterium glutamicum were investigated. The effect of carbon source on the production of L-phenylalanine was significant. Molasses enhanced the production of L-phenylalanine compared to sucrose, glucose, fructose, or their mixture. It was noticed that trace salts were required for the cell growth and product formation in the minimal medium, but excess amounts of trace salts had no effect on the production of L-phenylalanine. It was also found that optimum amounts of biotin and thiamine were required for the cell growth and the production of L -phenylalanine.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.2
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• pp.118-126
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• 2004

Recombinant E.coli ACV 1003 (recA::lacZ) releasing ${\beta}$-galactosidase by a SOS regulon system, when exposed to DNA-damaging compounds, have been used to effectively monitor endocrine disruptors. Low enzyme activity of less than 10 units/mL, corresponding to a $\mu\textrm{g}$/L(ppb) range of an endocrine disruptor (tributyl tin, bisphenol A. etc.), can be rapidly determined, not by a conventional time-consuming and tedious enzyme assay, but by an alternative interferometric biosensor. Heavily boron-doped porous silicon for application as an interferometer, was fabricated by etching to form a Fabry-Perot fringe pattern, which caused a change in the refractive index of the medium including ${\beta}$-galactosidase. In order to enhance the immobilization of the porous silicon surface, a calyx crown derivative (ProLinker A) was applied, instead of a conventional biomolecular affinity method using biotin. This resulted in a denser linked formation. The change in the effective optical thickness versus ${\beta}$-galactosidase activity, showed a linear increase up to a concentration of 150 unit ${\beta}$-galactosidase/mL, unlike the sigmoidal increase pattern observed with the biotin.

• Korean journal of applied entomology
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• v.14 no.3 s.24
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• pp.155-161
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• 1975

The results of studies on the synthesis of B group vitamins by plant pathogenic bacteria indicate that most bacteria utilize thiamine, nicotinic acid, biotin and P-Aminobenzoic acid as growth factors. Riboflavin (vitamin $B_2$) was produced by most bacterial genera including the Corynebacteria but with the exception of C. rathay and C.fasciant. The results suggest that the ability to produce riboflavin is not a generic characteristic of Corynebacterium, and that the accuracy of the ultra-violet light method (one of the diagnostic tests for potato bacterial ring rot disease caused by Corynebacterium sepedonicum) must he reconsidered.

• The Korean Journal of Zoology
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• v.18 no.2
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• pp.61-70
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• 1975

여포액이 여포안에서는 난자의 성숙을 억제하지만 여포액을 일단 여포 밖으로 내어 배양액을 섞거나 혹은 여포액만으로 난자를 배양할 때 난자는 성숙분열을 일으키는 것을 보아 왔다. 저자들은 소의 여포액 내의 성분중 어떤 것 들이 난자 성숙에 유효한 가를 밝히기 위하여 본 실험을 행하였다. 그 결과는 다음과 같다. 첫째, 여포액을 투석하여 얻은 dialysable fraction을 이용하여 난자를 배양하였을 때 높은 성숙율을 얻었다. 반대로 non-dialysable fraction를 포함하는 기본배양액 내에서는 난자의 성숙율은 극히 낮았으며 퇴화하는 경향이 있었다. 둘째, paper chromatography 의 방법으로 dialysable fraction이 포함하는 free amino acid를 조사한 결과 8가지의 amino acid가 동정되었다. 이 amino acid를 기본배양액에 섞어 배양액으로 만들어 난자를 배양했을 때 난자성숙율이 90%이상이었고 제 2차 중기까지 도달한 난자는 30시간 이내에 10% 정도였다. 셋째, 상기의 amino acid가 들어있는 배양액에 다시 biotin를 첨가하여 배양하면 48시간내에 제 2차 분열 중기까지 도달하는 난자가 60%에 이르렀다. 위 결과로 보아 여포액은 in vitro인 경우 난자의 성숙을 유발하며 성숙을 유발하는 주요 성분은 여포액내에 포함되어 있는 몇가지 amino acid와 biotin과 같은 vitamine B가 될 것이라는 결론을 얻었다.