• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.83-83
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• 2003

The lutropin/choriogonadotropin receptor (LHR) is a member of the rhodopsin-like subfamily of G protein coupled receptor (GPCRs), that has been shown to mediate the internalization of its two naturally occurring agonist, lutropin and choriogonadotropin (CG). The clustered agonist-receptor complex is internalized by a dynamin-dependent pathway and traverses the endosomal compartment without agonist dissociation Dissociation of the agonist-receptor complex occurs in the lysosomes, where both the agonist and receptor are degrade. Recently, constitutively activating mutations of the receptor have been identified that are associated with familial male-precocious puberty (FMPP). A FMPP is a form of sexual precocious puberty in boys in which testosterone levels are elevated independent of changes in luteinizing hormone-releasing hormone and serum luteinizing hormone levels, We have now analyzed two naturally occurring, constitutively active mutants of the human LHR. These mutations were introduced into the rat LHR (rLHR) and are designated L435R and D556Y. Cells expressing rLHR-D556Y bind human choriogonadotropin (hCG) with normal affinity, exhibit a 25-fold increase in basal cAMP and respond to hCG with a normal increase in cAMP accumulation. Cells expressing rLHR-L435R also bind hCG with normal affinity, exhibit a 47-fold increase in basal cAMP, and do not respond to hCG with a further increase in cAMP accumulation. This mutation enhances the internalization of the free and agonist-occupied receptors ~2- and ~17- fold, respectively We conclude that the state of activation of the rLHR can modulate its basal and/or agonist-stimulated internalization. Since the internalization of hCG is involved in the termination of hCG actions, we suggest that the lack of responsiveness detected in cells expressing rLHR-L435R is due to the fast rate of internalization of the bound hCG. The finding that membranes expressing rLHR-L435R respond to hCG with an increase in adenylyl cyclase activity supports this suggestion. Autonomous Leydig cell activity in FMPP is caused by a constitutively activating LH/CGR.

• Fisheries and Aquatic Sciences
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• v.14 no.4
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• pp.283-288
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• 2011

The jellyfish Nemopilema nomurai was hydrolyzed with papain and a novel dipeptide purified via ultrafiltration, gel filtration chromatography with Sephadex LH-20, and reverse phase chromatography using $C_{18}$ and $C_{12}$ columns. The IR, 1H NMR, 13C NMR, and MS spectrometer analyses showed that the dipeptide comprised tyrosine-isoleucine (Tyr-Ile). The $IC_{50}$ and $K_i$ values were $6.56{\pm}1.12$ and $3.10{\pm}0.28\;{\mu}M$, respectively, indicating competitive inhibition of angiotensin-I-converting enzyme (ACE). As a novel ACE-inhibitory active peptide, Tyr-Ile may have potential for use in antihypertensive therapy.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.6
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• pp.770-776
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• 2017

This study investigated the effects of recombinant eel gonadotropin hormone (rJeGTH) produced in silkworms, with and without a carboxyl-terminal peptide from equine chorionic gonadotropin (eCG), on the induction of sexual maturation in female eels Anguilla japonica. Experiments were conducted both in vivo and in vitro. In in vitro trials, germinal vesicle breakdown (GVBD) induction did not significantly differ between rJeFSH and $rJeFSH{\cdot}eCG$ treatments and the control group. However, previous studies did find that rJeLH and $rJeLH{\cdot}eCG$ treatments induced GVBD in female eels. Our in vitro exploration of $estradiol-17{\beta}$ ($E_2$) levels in immature ovarian tissues revealed significantly higher $E_2$ levels in the group treated with $rJeFSH{\cdot}eCG$ $1{\mu}g/mL$ than in the control group. In contrast, the in vivo experiments showed no effect of recombinant hormones on the sexual maturation of feminized eels. Previous studies and our own in vitro results have clearly shown that rJeGTH and $rJeGTH{\cdot}eCG$ have a positive effect on the sexual maturation of feminized eels. To develop the activity of rJeGTH in vivo, further studies should confirm circulation time and activity of these hormones in eels' bloodstream, modify the structure of the recombinant gene, and implement additional glycosylation.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.11
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• pp.1761-1769
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• 2007

This experiment was conducted to determine the extent to which susceptibility to cortisol-induced follicle shutdown is influenced by fleece phentotype. Twenty Finewool (10 sheep low fibre diameter, low coefficient of fibre diameter-LL and 10 low fibre diameter, high coefficient of variation of fibre diameter-LH) and twenty Strongwool (10 low fibre diameter, low coefficient of variation of fibre diameter-HL and 10 high fibre diameter and high coefficient of variation of fibre diameter-HH) sheep of 9 months of age were individually penned in an animal house and were injected intramuscularly with an aqueous suspension of hydrocortisone acetate at a rate of 1.42 mg/kg body weight for a period of two weeks. Fibre diameter was measured from clipped tattooed patch wool samples. Follicle activity was measured by histological changes in skin biopsies taken weekly. Blood samples were collected at two-week intervals and plasma cortisol measured. Increased plasma cortisol concentration significantly (p<0.05) reduced clean wool production and mean fibre diameter dropped to its lowest level four weeks after commencement and two weeks after the cessation of cortisol injection. Elevation of plasma cortisol concentration significantly (p<0.0001) increased the percentage of inactive follicles two weeks after injection started. High fibre diameter groups (Strongwool sheep; i.e. HL+HH) had significantly (p<0.0001) higher percentage of follicle shutdown than low fibre diameter groups (Finewool sheep; i.e. LL+LH). Average percentage of shutdown follicles for Finewool (LL+LH) and Strongwool (HL+HH) Merino sheep was $9.8{\pm}0.9$ and $13.5{\pm}0.9$ respectively. Shutdown of primary follicles was more pronounced in Finewool than Strongwool sheep. There was no significant effect of coefficient of variation of fibre diameter on propensity to follicle shutdown induced by exogenous cortisol. It is concluded that elevation in plasma cortisol concentration is inhibitory to the normal activity of follicles in Strongwool sheep but that variation in fibre diameter has little or no effect.

• Journal of Applied Biological Chemistry
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• v.54 no.1
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• pp.47-50
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• 2011

To develop a new natural whitening agent, we investigated the tyrosinase inhibitory effects of Persicaria tinctoria Flower extracts (PTFE). PTFE showed inhibitory activity on mushroom tyrosinase with the $IC_{50}$ values of $70.8{\pm}2.2{\mu}g/mL$. We purified two active compounds from PTFE by LH-20 column chromatography and prep-high performance liquid chromatography (HPLC) and identified as quercetin-3-O-rhamnoside (Q3R) and myricetin-3-O-rhamnoside (M3R) by $^1H$nuclear magnetic resonance (NMR) and liquid chromatography-mass spectrometry (LC-MS) analysis. Q3R and M3R showed tyrosinase inhibitory activities with the $IC_{50}$ values of $47.0{\pm}0.1{\mu}g/mL$ and $150.5{\pm}1.6{\mu}g/mL$, respectively. These results suggest that PTFE and its active compounds reduced melanin formation by the inhibition of tyrosinase activity. Thus, P. tinctoria flower extracts may be a candidate for cosmetic use.

• 월간 기계설비
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• s.241
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• pp.66-72
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• 2010

격심한 세계적 사회환경의 변화는 모든 산업분야에서 기존의 패턴을 탈피해 새로운 패러다임으로의 전환을 요구하고 있다. 이제는 이를 어느 정도 충실히 반영해 혁신을 이룰 수 있는가가 국가의 흥망을 좌우하는 중요한 요체가 되었다. 건설 기술의 R&D 분야는 최근의 화두인 친환경녹색성장에 관한 기술경쟁력 강화를 위해 혁신적인 연구 성과물을 내놓고 있다. 본지는 한국토지공사와 주택공사가 합쳐진 LH공사의 토지주택연구원 녹색성장연구실의 연구원들을 만나 기계 설비분야에서 새로운 재료 및 기술 등의 연구 개발과 실용화현황을 들어보았다.

• Proceedings of the Korean Vacuum Society Conference
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• 1998.02a
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• pp.114-115
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• 1998

Photoreflectance (pR) measurement h have been employed to study the uniformity of G GaAs!Si 3" wafer. The PR shows the energy of l light and heavy hole even at room temperature. F From the observed energy of LH and HH, it can b be seen that the center of the wafer is more s stressed than the 뼈ge. On the basis of biaxial t tensile stress the higher and lower. transitions are a attributed to heavy and light hole respectively.vely.

• Journal of Microbiology and Biotechnology
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• v.15 no.5
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• pp.1115-1119
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• 2005

The photoheterotrophic $H_2$ production of Rhodobacter sphaeroides was significantly increased through disruption of the genes coding for uptake hydrogenase and poly-${\beta}$-hydroxybutyrate (PHB) synthase (Lee et al., Appl. Microbiol. Biotechnol. 60: 147-153, 2002). In this work, we further removed the B800-850 light-harvesting (LH) complex from the strain and found an increase in $H_2$ production at the light-saturating cell growth (${\ge}10$ Watts $[W]/m^2$). Neither the mutant nor the wild-type produced more $H_2$ at the brighter light. Accordingly, light does not appear to be limited for the $H_2$ production by the presence of B800-850. However, increase in the level of the spectral complexes resulted in decrease of $H_2$ production. Thus, although the B875 is essential for light harvesting, the consumption of cellular energy for the synthesis of B800-850 and the surplus LH complexes may reduce the energy flow into the $H_2$ production of R. sphaeroides.

• KSBB Journal
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• v.27 no.2
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• pp.121-126
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• 2012

In order to explore structural features of minoxidil analogs with a view of enhancing lysyl hydroxylase (LH) inhibitory activity, molecular holographic QSAR (HQSAR) and CoMSIA (comparative molecular similarity indices analysis) were performed. The results from the atomic contributions with optimized the HQSAR 6-2 model indicated that, in case of pyrimidine-1-N-oxide substituent, C2 atom of pyrimidine ring and C'3-C'4 bond of 4-piperidinol group showed the highest impact on the inhibitory activity towards LH enzyme. It was also evident from the information of the optimized CoMSIA F5 model that the inhibitory activity mainly depended on the hydrophobic field contribution (36%) and the hydrogen bond (H-bond) field contribution (49.2%) of substrate molecule. Particularly, it is predicted that the functional groups which disfavor H-bond acceptors in large space around the piperidinol group and also the functional groups which favor the H-bond acceptors at C'4 (& C'5) atom in $R_5$ group play a role for increased inhibitory activity. With this in mind, it is likely that a novel candidate having more improved inhibitory activity on hair growth could be designed in the future.

• Applied Biological Chemistry
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• v.38 no.6
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• pp.577-580
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• 1995

During the screening for the antimicrobial agents against multidrug-resistant Staphylococcus aureus, we isolated an active compound produced by strain CNU30122. The active compound was purified from culture broth by HP-20 column chromatography, ethylacetate extraction. silica gel column and Sephadex LH-20 column chromatographies and HPLC. Based on various NMR studies including $^1H-^1H\;COSY$, $^1H-^{13}C\;COSY$ and HMBC experiments. the active compound was identified as fusidic acid.