Publications by authors named "Nahee Kim"

11 Publications

  • Page 1 of 1

Effects of Pig Skin Collagen Supplementation on Broiler Breast Meat.

Food Sci Anim Resour 2021 Jul 1;41(4):674-686. Epub 2021 Jul 1.

Department of Animal Science, Chungbuk National University, Cheongju 28644, Korea.

This study aimed to enhance the quality of broiler breast meat by adding pig skin collagen to feed. A total of 50 Ross 308 broilers were classified according to the following feeding regime for two weeks: basal diet (NC), basal diet+0.1% fish collagen (PC), basal diet+0.1% pig skin collagen (T1), basal diet+0.5% pig skin collagen (T2), and basal diet+1.0% pig skin collagen (T3). The moisture content was the highest in the PC group, and the protein content was the lowest in the T1 group (p<0.05). The fat content was higher in the T1 and PC groups, whereas the ash content was higher in the T3 group (p<0.05). Drip loss was the highest in the NC group and the lowest in the T2 group (p<0.05). Lightness was low in groups T2 and T3, redness was low in groups T2 and PC, and yellowness was low in groups T1, T2, and PC (p<0.05). The collagen content of the chicken breast was the highest in the T3 group, and that of the skin was the highest in the T1 group (p<0.05). The texture characteristics of springiness, cohesiveness, chewiness, and hardness were the highest in the T3 group (p<0.05). In conclusion, the supplementation of a broiler diet with pig skin collagen was found to increase the collagen content of the breast meat, indicating the improved quality of the broiler breast meat.
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http://dx.doi.org/10.5851/kosfa.2021.e28DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8277177PMC
July 2021

Efficacy of ethyl ascorbyl ether-containing cosmetic cream on blue light-induced skin changes.

J Cosmet Dermatol 2021 May 18. Epub 2021 May 18.

AMOREPACIFIC, Research and Development Center, Gyeonggi-do, Korea.

Background: Office workers are consistently exposed to blue light, mainly from sunlight and digital device. Recent studies report that blue light has various harmful effects, including cellular changes via reactive oxygen species. Studies on blue light-induced skin changes have only been conducted in vitro and have not been clinically confirmed.

Objective: We provide novel methods to evaluate the effect of the product on the recovery of skin changed by blue light.

Methods: Internet surveys were conducted for workers in their 20s and 40s regarding exposure time to blue light in various environments. To study the effects of long-term exposure to blue light (456 nm) on the skin, we designed three light intensity conditions, and various skin characteristics were observed. After blue light irradiation, various skin characteristics were analyzed before and after applying ethyl ascorbyl ether (EAE)-containing cosmetic cream for 2 weeks.

Results: When exposed to strong blue light for approximately 16 days, the L value, skin hydration, transparency, and elasticity decreased, and the melanin index, erythema index, a value, and b value increased. Furthermore, after short-term blue light irradiation (dose, 269 J/cm , the equivalent of blue light exposure for approximately 38 days in daily life), the L value and elasticity decreased, and the melanin index and erythema index increased. However, when EAE cream was applied on skin for 1-2 weeks, the skin recovered.

Conclusion: This study clinically confirms the skin changes caused by blue light and the effect of EAE in relieving such changes.
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http://dx.doi.org/10.1111/jocd.14232DOI Listing
May 2021

Age-related biophysical changes of the epidermal and dermal skin in Korean women.

Skin Res Technol 2019 Jul 13;25(4):504-511. Epub 2019 Feb 13.

Clinical Research Center, Institut d'Expertise Clinique (IEC) Korea, Suwon, Korea.

Introduction: The clinical characteristics of skin were investigated to study the inter-relationship and changes in the biophysical properties of the epidermal and dermal layers associated with aging using noninvasive methods.

Methods: Our study included 100 healthy women aged between the early 20s and late 60s. Biophysical characteristics of skin such as color (brightness and spots), transparency, wrinkle on crow's feet, elasticity, hydration, sebum content, glossiness, and transepidermal water loss measured under controlled conditions.

Results: This study performed in a Korean population demonstrated that aging significantly affects human skin in terms of parameters such as wrinkles, skin color, elasticity, and epidermal hydration. Age-related changes in skin hydration showed varying patterns between the epidermis and dermis. Skin color showed heterogeneous characteristics between the upper and lower epidermal layers associated with aging. Skin elasticity and wrinkles were observed to show and inversely proportional relationship in the early 40s.

Conclusions: We confirmed the significant influence of aging on the biophysical properties of skin and determined the distinct age-related biophysical changes in the epidermal and dermal layers of skin using noninvasive method. This study indicates the need for further research to investigate the distinctive age-related changes in characteristics of the epidermal and dermal layers of human skin.
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http://dx.doi.org/10.1111/srt.12679DOI Listing
July 2019

Biophysical properties of striae rubra and striae alba in human skin: Comparison with normal skin.

Skin Res Technol 2019 May 22;25(3):283-288. Epub 2018 Oct 22.

Clinical Research Center, Institut d'Expertise Clinique (IEC) Korea, Suwony, Gyeonggi-do, Korea.

Background: Striae distensae are common dermal lesions that progress through two different stages: the striae rubra, which appears to be erythematous, and striae alba, which is characterized by a hypopigmented feature. The clinical characteristics between striae distensae stages and normal skin remain unknown.

Objectives: We aimed to investigate the clinical characteristics according to stages of striae distensae in terms of their biophysical properties, using objective noninvasive measurements in comparison with adjacent normal skin.

Methods: Sixty-one healthy female subjects with striae distensae were included as follows: 30 with striae rubra and 31 with striae alba on the abdomen and thighs. Hydration of the epidermis and dermis, skin color brightness, and Erythema index were measured. Skin elasticity, roughness, and dermal echo-density of the skin with striae distensae and adjacent normal skin were also measured.

Results: Hydration of the epidermis and dermis showed no significant difference between the skin with striae distensae and normal skin. Brightness of skin with striae alba and normal skin was significantly higher than that of skin with striae rubra. Erythema index of skin with striae rubra was significantly higher than that of skin with striae alba and normal skin. Skin with striae rubra and striae alba had a rougher surface than normal skin. Elasticity and dermal echo-density were significantly lower in striae distensae skin.

Conclusions: Striae rubra and striae alba had similar biophysical properties in terms of skin hydration, elasticity, roughness, and dermal density. Moreover, striae distensae have less elasticity, more roughness, and lower dermal density than normal skin.
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http://dx.doi.org/10.1111/srt.12645DOI Listing
May 2019

Structural basis for the inhibition of human lysozyme by PliC from Brucella abortus.

Biochemistry 2013 Dec 12;52(51):9385-93. Epub 2013 Dec 12.

College of Pharmacy and Research Institute for Drug Development, Pusan National University , Busan 609-735, Republic of Korea.

Lysozymes are the first line of defense for a diverse range of organisms that catalyze the degradation of bacterial peptidoglycan. Gram-negative bacteria produce proteinaceous lysozyme inhibitors to protect themselves from the action of lysozymes. To date, MliC or PliC (membrane-bound or periplasmic inhibitor of c-type lysozyme, respectively) has been found in various Gram-negative bacteria. Here, we report the crystal structures of Brucella abortus PliC and its complex with human c-type lysozyme. The complex structure demonstrates that the invariant loop of MliC/PliC plays a crucial role in the inhibition of lysozyme via its insertion into the active site cleft of the lysozyme, as previously observed in the complex structure of Pseudomonas aeruginosa MliC and chicken c-type lysozyme. We identified a new binding interface between a loop adjacent to the active site of human lysozyme and a loop carrying Glu112 of B. abortus PliC, the structure of which was disordered in P. aeruginosa MliC. Because MliC/PliC family members have been implicated as putative colonization or virulence factors, the structures and mechanism of action of MliC/PliC will be relevant to the control of bacterial growth in animal hosts.
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http://dx.doi.org/10.1021/bi401241cDOI Listing
December 2013

Structure of the periplasmic copper-binding protein CueP from Salmonella enterica serovar Typhimurium.

Acta Crystallogr D Biol Crystallogr 2013 Oct 20;69(Pt 10):1867-75. Epub 2013 Sep 20.

College of Pharmacy, Pusan National University, Busan, Republic of Korea.

CueP was initially identified as a copper-resistance gene in Salmonella enterica serovar Typhimurium, which has evolved to survive in the phagosomes of macrophages. Recently, CueP was determined to be a periplasmic copper-binding protein and has been implicated in the transfer of copper ions to SodCII in the periplasm. In this study, the crystal structure of CueP has been determined, revealing a V-shaped dimeric structure. The conserved cysteine and histidine residues are clustered on the surface of one side of the C-terminal domain, suggesting that this cysteine- and histidine-rich region is related to the function of CueP. LC-MS/MS analysis established the presence of a disulfide bond between Cys96 and Cys176 under aerobic conditions. Subsequent biophysical analyses showed that the CueP protein binds copper and zinc, and the mutation of Cys104 to serine (C104S) dramatically reduced the binding affinity for copper and zinc, suggesting that the cysteine- and histidine-rich cluster is responsible for copper binding. This study provides a structural basis for the participation of CueP in the resistance of the intracellular pathogen Salmonella to copper.
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http://dx.doi.org/10.1107/S090744491301531XDOI Listing
October 2013

Functional implications of an intermeshing cogwheel-like interaction between TolC and MacA in the action of macrolide-specific efflux pump MacAB-TolC.

J Biol Chem 2011 Apr 16;286(15):13541-9. Epub 2011 Feb 16.

Department of Manufacturing Pharmacy, Research Institute for Drug Development, Pusan National University, Busan 609-735, Republic of Korea.

Macrolide-specific efflux pump MacAB-TolC has been identified in diverse gram-negative bacteria including Escherichia coli. The inner membrane transporter MacB requires the outer membrane factor TolC and the periplasmic adaptor protein MacA to form a functional tripartite complex. In this study, we used a chimeric protein containing the tip region of the TolC α-barrel to investigate the role of the TolC α-barrel tip region with regard to its interaction with MacA. The chimeric protein formed a stable complex with MacA, and the complex formation was abolished by substitution at the functionally essential residues located at the MacA α-helical tip region. Electron microscopic study delineated that this complex was made by tip-to-tip interaction between the tip regions of the α-barrels of TolC and MacA, which correlated well with the TolC and MacA complex calculated by molecular dynamics. Taken together, our results demonstrate that the MacA hexamer interacts with TolC in a tip-to-tip manner, and implies the manner by which MacA induces opening of the TolC channel.
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http://dx.doi.org/10.1074/jbc.M110.202598DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3075700PMC
April 2011

Periplasmic domain of CusA in an Escherichia coli Cu+/Ag+ transporter has metal binding sites.

J Microbiol 2010 Dec 9;48(6):829-35. Epub 2011 Jan 9.

College of Pharmacy and Research Institute for Drug Development, Pusan National University, Busan, 609-735, Republic of Korea.

The resistance nodulation division (RND)-type efflux systems are utilized in Gram-negative bacteria to export a variety of substrates. The CusCFBA system is the Cu(+) and Ag(+) efflux system in Escherichia coli, conferring resistance to lethal concentrations of Cu(+) and Ag(+). The periplasmic component, CusB, which is essential for the assembly of the protein complex, has Cu(+) or Ag(+) binding sites. The twelve-span membrane protein CusA is a homotrimeric transporter, and has a relatively large periplasmic domain. Here, we constructed the periplasmic domain of CusA by joining two DNA segments and then successfully expressed and purified the protein. Isothermal titration calorimetry experiments revealed Ag(+) binding sites with Kds of 10(-6)-10(-5) M. Our findings suggest that the metal binding in the periplasmic domain of CusA might play an important role in the function of the efflux pump.
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http://dx.doi.org/10.1007/s12275-010-0339-8DOI Listing
December 2010

Immunohistochemical study on the expression of calcium binding proteins (calbindin-D28k, calretinin, and parvalbumin) in the cerebellum of the nNOS knock-out(-/-) mice.

Anat Cell Biol 2010 Mar 31;43(1):64-71. Epub 2010 Mar 31.

Department of Anatomy, Seoul National University College of Medicine, Seoul, Korea.

Nitric Oxide (NO) actively participates in the regulation of neuronal intracellular Ca(2+) levels by modulating the activity of various channels and receptors. To test the possibility that modulation of Ca(2+) buffer protein expression level by NO participates in this regulatory effect, we examined expression of calbindin-D28k, calretinin, and parvalbumin in the cerebellum of neuronal NO synthase knock-out (nNOS((-/-))) mice using immunohistochemistry. We observed that in the cerebellar cortex of the nNOS((-/-)) mice, expression of calbindin-D28k and parvalbumin were significantly increased while expression of calretinin was significantly decreased. These results suggest another mechanism by which NO can participate in the regulation of Ca(2+) homeostasis.
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http://dx.doi.org/10.5115/acb.2010.43.1.64DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2998781PMC
March 2010

Region-specific changes in the immunoreactivity of vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptide receptors (VPAC2, and PAC1 receptor) in the aged rat brains.

Brain Res 2010 Sep 1;1351:32-40. Epub 2010 Jul 1.

Department of Anatomy, Seoul National University College of Medicine, 28 Yongon-Dong, Chongno-Gu, Seoul 110-799, Korea. Electronic address:

Pituitary adenylate cyclase-activating peptide (PACAP) and vasoactive intestinal peptide (VIP) have been implicated in a large array of physiological and patho-physiological processes through their receptors (VPAC(1), VPAC(2), and PAC(1) receptor) in the central nervous system. Previously, we demonstrated age-related decreases in VPAC(1) receptor expression in the rat brain providing a possible basis of several age-induced functional changes in the aged brain. In the current study, we also examined age-related changes in PAC(1) and VPAC(2) receptors in aged rat brains using an immunohistochemical approach. We found that PAC1 immunoreactivity was significantly increased in the hippocampal formation, hypothalamus, thalamus, midbrain septal nuclei, and white matter of aged rats compared with young control rats although its distribution pattern was not altered. In contrast, both distribution pattern and immunoreactivity of VPAC(2) receptor remained unchanged in aged rat brains. These results suggest that the PACAP/VIP receptors exhibit specific expressional changes in the aged brain and that these specific changes could underlie age-associated memory and cognitive functional declines as well as several other age-induced functional changes in the brain. However, the exact regulatory mechanism and its functional significance require further elucidation.
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http://dx.doi.org/10.1016/j.brainres.2010.06.048DOI Listing
September 2010

Crystal structure and functional insight of HP0420-homolog from Helicobacter felis.

Biochem Biophys Res Commun 2010 Apr 17;394(4):940-6. Epub 2010 Mar 17.

College of Pharmacy and Research Institute for Drug Development, Pusan National University, Jangjeon-dong, Geumjeong-gu, Busan 609-735, Republic of Korea.

Helicobacter pylori infect more than half of the world's population and are considered a cause of peptic ulcer disease and gastric cancer. Recently, hypothetical gene HP0421 was identified in H. pylori as a cholesterol alpha-glucosyltransferase, which is required to synthesize cholesteryl glucosides, essential cell wall components of the bacteria. In the same gene-cluster, HP0420 was co-identified, whose function remains unknown. Here we report the crystal structure of HP0420-homolog of H. felis (HF0420) to gain insight into the function of HP0420. The crystal structure, combined with size-exclusion chromatography, reveals that HF0420 adopts a homodimeric hot-dog fold. The crystal structure suggests that HF0420 has enzymatic activity that involves a conserved histidine residue at the end of the central alpha-helix. Subsequent biochemical studies provide clues to the function of HP0420 and HF0420.
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http://dx.doi.org/10.1016/j.bbrc.2010.03.087DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2891984PMC
April 2010
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