• BMB Reports
• /
• 제33권2호
• /
• pp.120-125
• /
• 2000

M2PI is an active single chain mini-proinsulin with a 9-residue linker containing the turn-forming sequence 'YPGDV' between the B- and A-chains, but which retains about 50% of native insulin receptor binding activity. The refolding efficiency of M2PI is higher than proinsulin by 20-40% at alkaline pH, and native insulin is generated by the enzymatic conversion of M2PI. The solution structure of M2PI was determined by NMR spectroscopy. The global structure of M2PI is similar to that of native insulin, but the flexible linker between the B- and A-chains perturbed the N-terminal A-chain and C-terminal B-chain. The helix in the N-terminal A-chain is partly perturbed and the ${\beta}$-turn in the B-chain is disrupted in M2PI. However, the linker between the two chains was completely disordered indicating that the designed turn was not formed under the experimental conditions (20% acetic acid). Considering the fact that an insulin analogue, directly cross-linked between the C-terminus of the B-chain and the N-terminus of the A-chain, has negligible binding activity, a flexible linker between the two chains is sufficient to keep binding activity of M2PI, but the perturbed secondary structures are detrimental to receptor binding.

• Archives of Pharmacal Research
• /
• 제27권4호
• /
• pp.371-375
• /
• 2004

The silicon linker is the foremost traceless linker used in solid-phase reactions. Hydrogen fluo-ride (HF) or trifluoroacetic aicd (TFA) can remove the silicon linker with the silicon atom being replaced by a hydrogen atom. In this experiment, the linkers 1c and 2d, which are the most useful in solid-phase reactions, were synthesized, Linker 1c is composed of seven linearly linked carbons and linker 2d includes an oxygen atom in the linear carbon chain to increase the solvation capacity. The carboxylic acid component of linker 1c and 2d forms an amide or ester bond with resin. The synthesized linkers 1c and 2d could be utilized in constructing a chemical compound library that includes indole, benzodiazepine and phenothiazine (aromatic ring compounds).

• Archives of Pharmacal Research
• /
• 제26권10호
• /
• pp.785-795
• /
• 2003

For the development of new anticonvulsive agents, GABAmimetics such as nipecotic acid, isonipecotic acid, ${\gamma}-aminobutyric$ acid (GABA), ${\gamma}-vinyl$ GABA (vigabatrin) and valproic acid were covalently coupled through an ester bond by a two-carbon linker chain as potential prodrugs and evaluated for their anticonvulsive activities.

• 한국연초학회지
• /
• 제37권1호
• /
• pp.25-33
• /
• 2015

Genome walking is a par ticular application for identifying sequences of unknown genomic regions adjacent to a known region. Many genome walking methods based on polymerase chain reaction (PCR) are available. Even if earlier techniques suffer from low reproducibility, inefficiency, and non-specificity, improved strategies have been developed. In this study, we present an alternative strategy: the genomic DNA is digested with restriction enzymes. After cytosine overhangs at 5' ends, the fragments are ligated to linker adaptor s had guanine overhang at 3' ends. Then nested PCR is performed. The improvements in this strategy focus on two points. The first is the C tailing method using Pfu polymerase instead of the A tailing method based on nontemplate-dependent terminal transferase activity of Taq polymerase. Therefore unintended modification of target DNA can be prevented without A tailing error. The second point is the use of C/G-specific ligation had advantage in the ligation efficiency compared with A/T-specific ligation. Therefore, the C-G linker PCR method increases ligation efficiency between digested genomic DNA and adaptor DNA. As a result, the quantity of target DNA to amplify by PCR is enriched. We successfully used G-C linker PCR to retrieve flanking regions bordering the phophinothricin resistance gene in genetically modified tobacco (GMO).

• BMB Reports
• /
• 제30권3호
• /
• pp.177-181
• /
• 1997

We constructed a single-chain immunoglobulin in which the carboxyl end of the heavy chain variable domain is covalently joined to the amino terminus of the light chain variable domain via peptide linker and the carboxyl end of the light chain variable domain is linked to human ${\gamma}1$ Fc region through the hinge region. The molecule was expressed in Chinese hamster ovary cells, assembled into a dimeric molecule and secreted into the culture medium. The dimeric molecule (2E11) was purified from the culture supernatant by affinity chromatography on Protein G-Sepharose column. The size of the unreduced or reduced protein was the expected molecular weight of approximately 120 or 60 kDa, respectively, as assessed by SDS-polyacrylamide gel electrophoresis. The antigen-binding affinity of 2E11 was almost the same as that of a native antibody counterpart (CS131A), suggesting that the single-chain immunoglobulin may function like a native antibody.

• 한국가축번식학회지
• /
• 제27권3호
• /
• pp.197-206
• /
• 2003

hFSH는 $\alpha$와 $\beta$ subunit으로 구성된 heterodimer로서 두 subunit의 조합은 활성을 지닌 호르몬의 생산에 있어서 매우 중요한 단계이다. 이 조합과정의 효율을 증대하기 위하여 본 연구에서는 hFSH를 단일사슬의 단백질로 구축하고자 하였으며, 이의 일환으로 각 subunit 대한 cDNA단편을 연결하는 서열로 CTP linker를 도입하였다. 재조합한 hFSH-CTP 유전자는 pseudotype의 retrovirus vector system을 이용하여 CHO 세포와 닭의 배로 각각 전이되었다. CHO 세포에서의 FSH의 생산은 $\alpha$와 $\beta$를 각각 전이한 경우에 비해 hFSH-CTP를 전이한 경우에서 17배 이상 높은 것으로 나타났다. 닭에서는 유전자 전이를 시도한 62개체 중에서 11마리가 부화하였으며 그 중 10마리가 형질전환된 닭인 것으로 RT-PCR을 통하여 확인되었다. 그러나 개체의 혈중 FSH의 생산은 확인하지 못하였다. 이상의 실험 결과를 바탕으로 하여 재조합된 hFSH-CTP는 FSH의 발현에 매우 효율적인 구조로 생각되며, 또한 retrovirus를 이용한 유전자 전이 방법은 형질전환 가금의 생산에 있어서 매우 적절한 방법으로 사료된다.

• Bulletin of the Korean Chemical Society
• /
• 제32권4호
• /
• pp.1133-1137
• /
• 2011

Ordered array of gold nanoparticles (Au NPs) over ITO glass was investigated in terms of ITO pretreatment, particle size, and diamines with different chain length. Owing to the indium-tin-oxide (ITO) layer coated on the glass, the substrate surface has a limited number of hydroxyl groups which can produce functionalized amine groups for Au binding, which resulted in the loosely-packed array of Au NPs on the ITO surface. Diamine ligand as a molecular linker was introduced to enhance the lateral binding of adjacent Au NPs immobilized on the amine-functionalized ITO glass, consequently leading to the densely-packed array of Au NPs over the ITO substrate. The molecular bridging effect was strengthened with the increase of chain length of diamines: C-12 > C-8. The packing density of small Au NPs (< 40 nm) was significantly increased with the increase of C-8 diamine, but large Au NPs (> 60 nm) did not produce densely-packed array on the ITO glass even for the dosage of C-12 diamine.

• 미생물학회지
• /
• 제51권2호
• /
• pp.115-125
• /
• 2015

단일클론항체 AP64 IgM은 인간의 급성 비임파성 골수암(ANLL) 세포주 HL60에 결합하며 쥐의 ANLL 세포에도 교차결합(cross-react)한다. 또한 complement에 의해 매개되어지면 골수암 억제효과를 나타낸다. 본 연구에서는 RT-PCR에 의해 AP64 IgM을 분비하는 하이브리도마의 $V_H$ 및 $V_L$ cDNA로부터 유래된 재조합 single-chain variable domain fragment (ScFv)를 제조하였다. $V_H$ 및 $V_L$은 15개 아미노산으로 구성된 linker $(G_4S)_3$으로 연결되었다. 재조합 ScFv는 Escherichia coli BMH 71-18에서 single polypeptide chain으로 발현되었다. Periplasmic extract를 $Ni^+$-NTA-agarose affinity column에 가하여 발현된 재조합 ScFv를 정제하였으며 westernblot으로 정제된 단백질을 탐지하였다. 정제된 재조합 ScFv는 AP64 IgM 모항체가 탐지하는 항원과 같은 HL60 세포의 표면항원(약 30 kDa)을 인지하였다. 그러나 HL60의 표면항원에 대한 ScFv의 결합력은 AP64 IgM 모항체보다 낮아서 추후 이에 대한 개선이 필요하다. 종합하여 볼 때 HL60 세포주에 특이적인 재조합 ScFv는 진단 또는 치료목적으로 유용한 생물학적 제재가 될 수 있을 것이다.

• 대한약학회:학술대회논문집
• /
• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
• /
• pp.246.1-246.1
• /
• 2003

Hetero chain compounds have high possibilities of being good medicinal candidate because of their well-known medicinal activity and relatively low subtitled carbon. By constructing the method of making this compound library, this research has the purpose to create a new medicinal candidate materials based on an easy medicinal search. The first step is to construct an Indole library in a compounding process with the design of a linker connecting a solid-state resin and a substrate. (omitted)

• Journal of Microbiology and Biotechnology
• /
• 제18권6호
• /
• pp.1186-1190
• /
• 2008

Single-chain Fv (scFv) antibody against c-Met is expected to be employed in clinical treatment or imaging of cancer cells owing to the important biological roles of c-Met in the proliferation of malignancies. Here, we show that the productivity of scFv against c-Met in Escherichia coli is significantly influenced by the orientation of its variable domains. We generated anti-c-Met scFv antibodies with two different domain orders (i.e., $V_L$-linker-$V_H$ and $V_H$-linker-$V_L$), expressed them in the cytoplasm of E. coli trx/gor deleted mutant, and compared their specific activities as well as their productivities. Productivity of total and functional anti-c-Met scFv with $V_H/V_L$ orientation was more than five times higher than that with $V_L/V_H$ format. Coexpression of DsbC enhanced the yield of soluble amounts of anti-c-Met scFv protein for both constructs. The purified scFv antibodies of the two different formats exhibited almost the same antigen-binding activities. We also compared the productivities and specific activities of anti-c-Met diabodies with $V_H/V_L$ or $V_L/V_H$ formats and obtained similar results to the case of scFv antibodies.