• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.1 s.60
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• pp.53-60
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• 2007

(6R)-5,6,7,8-tetrahydrobiopterin ($6-BH_4$) cofactor is essential for various process, and is present in probably every cell or tissue of higher organism. $6-BH_4$ is required lot various enzyme activities, and for less defined functions at the cellular level. And it is well known about the antioxidant effects as a non-protein compound. Recently, scientists proposed another roles for $6-BH_4$ in melanogenesis. $6-BH_4$ is a well known tyrosinase inhibitor. In this study, we found that methyl-$BH_4$ and $6-BH_4$ have antioxidant activities and inhibitory activity for melanin synthesis. These pterin compounds were not toxic in HaCaT and B16F10 cells and showed scavenging activity against DPPH radicals. We also showed that pterin compounds decreased protein levels of tyrosinase and TRP-1. In a clinical test, pterin compounds showed the significant skin whiteining effect after treatment for 3 weeks. Furthermore pterin compounds significantly suppressed the UVB-induced expression of $PGE_2$ and IL-6 genes induced UVB In HaCaT and inhibited UVB-induced melanogenesis in B16F10 cells. These results showed the effect of pterin compounds as a cosmeceutical ingredient.

• Korean journal of applied entomology
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• v.58 no.2
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• pp.133-142
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• 2019

This study analyzed genetic variation of the Oriental fruit fly (OFF), Bactrocera dorsalis, which is designated to be a quarantine insect pest in Korea. OFF samples endemic to Taiwan were collected at three different locations (Taipei, Taichung, and Kaohsiung) for three days from July 30 to August 1 in 2018 and assessed in their age and mitochondrial DNA sequence variations. In these places, 1,085 OFF males were collected using methyl eugenol lure while 30 males of Zeugodacus cucurbitae and one male of Bactrocera tau were collected using Cuelure. A protein diet lure attracted 6 flies including one OFF and 5 flies of Z. cucurbitae. Male heads of OFF contained pterin, which increased in contents with age from 32 to $59{\mu}g/head$. There was a local variation in pterin amounts in OFF heads, in which Kaohsiung population had lower amounts of pterin than Taipei and Taichung populations. Genetic distance among these three populations were measured by random amplified polymorphic DNA and showed that Taipei population was separated from Taichung/Kaohsiung cluster. Genetic variation was also analyzed in sequence variations in cytochrome oxidase I (CO-I) and NADH dehydrogenase I (ND-I). There was 7.8% variation in CO-I sequence (360 residues) and 6.6% variation in ND-I sequence (213 residues). These polymorphic sites are proposed to be used to develop SNP (single nucleotide polymorphism) markers characteristic to Taiwan OFF populations.

• Archives of Pharmacal Research
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• v.21 no.6
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• pp.692-697
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• 1998

GTP cyclohydrolase I catalyzing the first reaction in the biosynthesis of pterin moiety of folic acid in bacteria, was purified from Streptomyces tubercidicus by at least 203-fold with a yield of 32% to apparent homogeneity, using ammonium sulfate fractionation, DEAE-cellulose, Sepharose CL-6B, and hydroxylapatite column chromatography. The molecular weight of the native enzyme was estimated to be 230,000 daltons by gel permeation chromatography. The purified enzyme gave a single band on sodium dodesyl sulfate-polyacrylamide gel electrophoresis and its molecular weight was apparently 58,000 daltons. These results indicate that the enzyme consists of four subunits with the same molecular weight. The $K_m$ and $V_{max}$ values for GTP of the purified enzyme were determined to be 80${\mu}$M and 90nmol/min (mg protein), respectively. The optimum pH and temperature for the enzyme reaction were pH 7.5-8.5 and $40-42^{\circ}C$, respectively. Coenzyme or metal ion was not required for the enzyme activity. The enzyme activity was inhibited by most divalent cations, while it was slightly activated by potassium ion. In case of nucleotides, CTP, GMP, GDP, and UTP inhibited enzyme activity, among which GDP exhibited the strongest inhibitory effect.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.13 no.1
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• pp.30-36
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• 2013

6-pyruvoyltetrahydropterin synthase (PTPS) deficiency is autosomal recessive disorder and the most common type of tetrahydrobiopterin (BH4) deficiency. It is caused by deficiency of PTPS, a cofactor involved in the biosynthesis of BH4 from guanosine triphosphate (GTP). Unlike classical phenylketonuria, which needs restriction of dietary phenylalanine for whole life, BH4 deficiency is treated by tetrahydrobiopterin, levodopa, and 5-hydroxytryptophan replacement. So it is important to make accurate diagnosis and initiate treatment as soon as possible for a better prognosis. There is no retrospective study of Korean patients undergoing long-term treatment for PTPS deficiency. We report 9 Korean patients with PTPS deficiency and their laboratory findings including BH4 loading tests, urine pterin tests, genotypes, dihydropteridine reductase (DHPR) activities and clinical manifestations including medication and developmental delay existence.