• Title/Summary/Keyword: zipper

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Cell Selectivity of an Antimicrobial Peptide Melittin Diastereomer with D-amino Acid in the Leucine Zipper Sequence

  • Zhu, Wan Long;Nan, Yong Hai;Hahm, Kyung-Soo;Shin, Song-Yub
    • BMB Reports
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    • v.40 no.6
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    • pp.1090-1094
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    • 2007
  • Melittin (ME), a linear 26-residue non-cell-selective antimicrobial peptide, displays strong lytic activity against bacterial and human red blood cells. To design ME analogue with improved cell selectivity, we synthesized a melittin diastereomer (ME-D) with D-amino acid in the leucine zipper sequence (Leu-6, Lue-13 and Ile-20). Compared to ME, ME-D exhibited the same or 2-fold higher antibacterial activity but 8-fold less hemolytic activity. Circular dichroism analysis revealed that ME-D has much less $\alpha$-helical content in $\alpha$-helical content in the presence of zwitterionic EYPC/cholesterol (10 : 1, w/w) liposomes compared to negatively charged EYPE/EYPG (7 : 3, w/w) liposomes. The blue shift of the fluorescence emission maximum of ME-D in zwitterionic EYPC/cholesterol (10 : 1, w/w) liposomes was much smaller than in negatively charged EYPE/EYPG (7 : 3, w/w) liposomes. These results suggested that the improvement in therapeutic index/cell selectivity of ME-D is correlated with its less permeability to zwitterionic membranes.

Potentiation of TRAIL killing activity by multimerization through isoleucine zipper hexamerization motif

  • Han, Ji Hye;Moon, Ae Ran;Chang, Jeong Hwan;Bae, Jeehyeon;Choi, Jin Myung;Lee, Sung Haeng;Kim, Tae-Hyoung
    • BMB Reports
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    • v.49 no.5
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    • pp.282-287
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    • 2016
  • Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a homo-trimeric cytotoxic ligand. Several studies have demonstrated that incorporation of artificial trimerization motifs into the TRAIL protein leads to the enhancement of biological activity. Here, we show that linkage of the isoleucine zipper hexamerization motif to the N-terminus of TRAIL, referred as ILz(6):TRAIL, leads to multimerization of its trimeric form, which has higher cytotoxic activity compared to its native state. Size exclusion chromatography of ILz(6):TRAIL revealed possible existence of various forms such as trimeric, hexameric, and multimeric (possibly containing one-, two-, and multi-units of trimeric TRAIL, respectively). Increased number of multimerized ILz(6):TRAIL units corresponded with enhanced cytotoxic activity. Further, a high degree of ILz(6):TRAIL multimerization triggered rapid signaling events such as activation of caspases, tBid generation, and chromatin condensation. Taken together, these results indicate that multimerization of TRAIL significantly enhances its cytotoxic activity.

Response Modification Factors of Inverted V-type Ordinary Concentrically Braced Frames (역V형 보통가새골조의 반응수정계수)

  • Kim, Jin-Koo;Nam, Kwang-Hee
    • Journal of the Earthquake Engineering Society of Korea
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    • v.8 no.3
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    • pp.53-62
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    • 2004
  • In this paper the overstrength factors, ductility factors, and response modification factors of ordinary concentric braced frames designed in accordance with a current seismic design code are determined by performing pushover analysis. According to the analysis results, the overstrength and the response modification factors turn out to be larger than the values regulated in the codes in most model structures. However if the braces are reinforced by BRB or zipper columns, the overstrength factors and response modification factors turn out to increase significantly.

Development and Evaluation of Customized Clothing for Patients with Severe Dementia (중증 치매환자복 개발 및 사용성 평가)

  • Kwang Ae Park;Chung Eun Yang
    • Fashion & Textile Research Journal
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    • v.25 no.3
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    • pp.346-357
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    • 2023
  • The purpose of this study is to develop clothing customized for dealing with patients with severe dementia. Based on the results of previous studies, The research patient clothing was designed to reduce the physical fatigue experienced by caregivers when dressing and undressing patients by changing the position and shape of the split in the patient's clothing. This study used qualitative and quantitative methods to measure the extent to which these modifications improved the ease of dressing and undressing the research patient. The research patient clothing was developed by moving the rear-center zipper to the side and changing the zipper from being half-open to fully open. Muscle energy consumption and fatigue generation were analyzed using EMG signals at the following sites: brachioradialis, biceps, triceps, anterior deltoid, medial deltoid, posterior deltoid, upper trapezius and erector spinae. Results indicated that the modified research patient clothing required less muscle energy and the occurrence of muscle fatigue decreased overall compared to traditional patient clothing. This was supported by the qualitative subjective evaluation, which revealed that dressing and undressing was easier with the modified clothing. In conclusion, repositioning of the back zipper to the side and the fully open slit shape significantly reduced caregiver fatigue when dressing and undressing patients.

Altering ready-made garments for the Handicapped : for the wheelchair users (장애인을 위한 기성복 개조법 제안 -휠체어를 사용하는 장애인을 중심으로-)

  • 홍성순;석혜정
    • Journal of the Korean Society of Clothing and Textiles
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    • v.27 no.8
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    • pp.873-882
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    • 2003
  • The purpose of the study is altering ready-made garments for the wheelchair users. Some alterations ready-made garments suggested for the wheelchair users are applicable to the physical conditions using the wheelchair, which create limitations in the use of clothing. Alterations ready-made garments were suggested 3 parts of the altering on the tops and 3 parts of the pants. Detachable sleeves at the elbow, adding the action pleats on the shoulder and back openings with zipper were adapted on the tops. The altering crotch length from the center back, changing position of the pocket and adding the pleats at the knee were adapted on the pants. The snap-tapes, zipper and hook & eye were used for the altering the ready-made garments.

Disaggregation Simulation Analysis on Distinct Aβ40 Fibril Models

  • Cho, Tony;Yu, Youngjae;Shin, Seokmin
    • Proceeding of EDISON Challenge
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    • 2016.03a
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    • pp.55-61
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    • 2016
  • $A{\beta}_{40}$ peptides form oligomers that later aggregate into a plaque, which is deemed to be a leading cause of Alzheimer's Disease. Its non-crystalline morphology has limited an understanding of comprehensive structural study. In this research, computational biomolecular simulations were performed in the following order: solvent and ion addition in a box, energy minimization of protein, equilibration, and periodic boundary condition disaggregation of a monomer from fibril. The result founded the two-fold model is 25% more stable in the simulation environment, and the steric zippers held on most tightly until 220 ps of simulation. The study supports the previous findings that two-fold aggregate $A{\beta}_{40}$ is more stable at 310 K and discusses further how much contribution steric-zipper and hydrogen bonding are making.

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A Passively Growing Sheath for Reducing Friction of Linearly Moving Structures (리니어 구동 구조의 마찰 저감을 위한 수동형 성장 피복)

  • Seo, Hanbeom;Kim, Dongki;Jung, Gwang-Pil
    • The Journal of Korea Robotics Society
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    • v.17 no.2
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    • pp.159-163
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    • 2022
  • A linearly moving structure in the area where the friction force is dominant - such as ducts filled with grease in the nuclear power plant - experiences increase in friction since the contact surface gets larger as the structure proceeds. To solve this problem is critical for the pipe inspection robot to investigate further area and this makes the system more energy-efficient. In this paper, we propose a passively growing sheath that can be added to linearly moving structures using zipper mechanism. The mechanism enables the linearly moving structures to maintain rolling contact condition against external environment, which provides substantial reduction in kinetic friction. To analyze the effect of the mechanism's head shape, we establish a physical model and compare to the experimental results. Finally, we have shown that the passively growing sheath can be successfully applied to the pipe inspection robot for the nuclear power plant.