• 생약학회지
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• 제33권1호통권128호
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• pp.69-73
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• 2002

The methanol extracts of 162 herbal medicines were screened for the inhibitory activity against VHR dualspecificity protein tyrosine phosphatase (DS-PTPase). Seventeen medicinal plants, Scutellaria baicalensis, Cuscuta chinensis, Caesalpinia sappan, Arecae pericarpium, Rubus coreanus, Machilus thunbergii, Amsonia elliptica Cinnamomum cassia, Arisaema erubescens, Pueraria thunbergiana, Dendrobium moniliforme, Mentha arvensis, Peucedanum japonicum, Salvia miltiorrhiza, Leonurus sibiricus, Siegesbeckia orientalis, Prunella vulgaris showed potent VHR DS-PTPase inhibitory activity.

• Journal of Microbiology and Biotechnology
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• 제19권9호
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• pp.918-921
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• 2009

In the present study, we examined the inhibitory effects of protein tyrosine phosphatase (PTPase) inhibitors, including sodium orthovanadate (SOV), ammonium molybdate (AM), and iodoacetamide (IA), on cell growth, accumulation of astaxanthin, and PTPase activity in the photosynthetic algae Haematococcus lacustris. PTPase activity was assayed spectrophotometrically and was found to be inhibited 60% to 90% after treatment with the inhibitors. SOY markedly abolished PTPase activity, significantly activating the accumulation of astaxanthin. These data suggest that the accumulation of astaxanthin in H. lacustris results from the concerted actions of several PTPases.

• ALGAE
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• 제19권3호
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• pp.271-276
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• 2004

One hundred and fifty four micro algal strains, newly isolated from nationwide freshwaters in Korea, were screened for their anticancer, ant diabetic, and antibiotic activities. The micro algal strains were cultured with different nutritional conditions that were divided into 4 groups as follows; a normal Allen medium, nitrogen (N)-limited medium, phosphorus (P)-limited medium, and N and P-limited medium. Algal biomass was extracted with a mixture of acetone:H₂O (1:1, v:v) and the extracts were used for the screening of bioactive materials. Anticancer, ant diabetic, and antibiotic materials were screened by the methods of vaccinia Hl-related protein tyrosine phosphates (VHR DS-PTPase) inhibition, protein tyrosine phosphates 1B (PTP1B) inhibition, and paper disk. The inhibition activity of VHR DS-PTPase was observed in 18 strains, having a maximum 79% inhibition from Anabaena affinis and the inhibition activity of PTP1B was observed in 9 strains, having a maximum 97% from Sphaerocystis schroeteri. Microcystis aeruginosa incubated in an N and P-limited medium showed antibiotic activity in 8 species out of 13 pathogenic bacteria. As a whole, it seemed that the stressed condition such as N and/or P limitation increased the production of bioactive materials in micro algae.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1996년도 춘계학술대회
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• pp.163-163
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• 1996

Peptide 유도체, 특히 tyrosine을 함유한 peptide 유도체는 항암제 개발을 위한 연구의 관심이 되고 있다. Thiophosphotyrosine을 함유한 peptide는, 종양 발현에 관련되는 여러 효소의 억제제로써, 즉 protein tyrosine kinase(PTK)의 억제제 및 protein tyrosine phosphatase(PTPase)의 억제제 혹은 cytosolic protein의 결합을 방지하는 차단제로 사용할 수 있으며 궁극적으로 항암제 개발에 응용할 수 있다. 이에, t-BOC chemistry를 이용하여 t-BOC-tyrosine을 출발물질로 하고, cyanoethyl 기를 phosphate protecting group으로 사용하여 thiophosphotyrosine을 함유한 peptide 유도체의 합성에 필요한 중요한 중간체 인 N-(tert-butoxycarbonyl)-O-(dicyanoethylthio-phosphene)-L-tyrosine을 합성하였다.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2001년도 Proceedings of 2001 International Symposium
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• pp.135-136
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• 2001

The Tk-ptp gene encoding a protein tyrosine phosphatase (PTPase) from the hyperthermophilic archaeon Thermococcus kodakaraensis KODI was cloned and sequenced. Sequence analysis indicated that Tk-ptp encoded a protein consisting 147 amino acid residues (16,953 Da). The wild type and the mutants were expressed in Escherichia coli cells as His-tagged fusion proteins and examined for enzyme characteristics. Tk-PTP possessed two unique features that were not found in eucaryal and bacterial counterparts. First, the recombinant Tk-PTP showed the phosphatase activity not only for the phosphotyrosine but also phosphoserine. Second, the conserved Asp (Asp-63), which was considered to be a critical residue, was not involved in catalysis. In order to know a specific substrate for Tk-PTP, C93S mutant was used to trap substrate protein. Proteins of 120, 60 and 53 kDa were isolated specifically from KODI cell lysates by affinity chromatography with Tk-PTP-C93S. It is suggested that these proteins are tyrosine-phosphorylated substrates of Tk-PTP.

• 한국식품과학회지
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• 제34권3호
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• pp.505-509
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• 2002

천마의 methanol 추출물로부터 VHR DS-PTPase 저해 물질을 분리하여 이를 HREI-MS와 $^1H-NMR$, $^{13}C-NMR$, DEPT 등의 기기 분석 자료에 의하여 baicalein으로 구조를 동정 하였다. 이 물질은 VHR에 대하여 $2.4{\mu}M$의 $IC_{50}$값을 나타내었고 T-cell PTPase나 PPase 1과 같은 다른 단백질 탈인산화 효소에 대하여는 저해 활성을 나타내지 않았다. 또한 7종류의 인간 암세포주(흑색종 세포주인 LOX-IMVI, 폐암 세포주인 NCI H23과 A549, 대장암 세포주인 HCT 116와 SW 620, 전립선암 세포주인 PC-3와 백혈병 세포주인 MOLT 4F)에 대한 세포독성을 조사하여 본 결과 $5.26{\sim}12.93\;{\mu}g/mL$에서 $GI_{50}$값을 나타내었다.