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An Interdisciplinary Investigation of Conformational Changes in Quasi-Crystalline Protein Array R-Bodies in Response to pH- [electronic resource]
An Interdisciplinary Investigation of Conformational Changes in Quasi-Crystalline Protein Array R-Bodies in Response to pH- [electronic resource]
상세정보
- 자료유형
- 학위논문파일 국외
- 최종처리일시
- 20240214101226
- ISBN
- 9798379908553
- DDC
- 574
- 저자명
- Cai, Guangyang.
- 서명/저자
- An Interdisciplinary Investigation of Conformational Changes in Quasi-Crystalline Protein Array R-Bodies in Response to pH - [electronic resource]
- 발행사항
- [S.l.]: : University of Washington., 2023
- 발행사항
- Ann Arbor : : ProQuest Dissertations & Theses,, 2023
- 형태사항
- 1 online resource(72 p.)
- 주기사항
- Source: Dissertations Abstracts International, Volume: 85-01, Section: B.
- 주기사항
- Advisor: Kollman, Justin M.;Asbury, Charles A.
- 학위논문주기
- Thesis (Ph.D.)--University of Washington, 2023.
- 사용제한주기
- This item must not be sold to any third party vendors.
- 초록/해제
- 요약R-bodies are ribbon-like protein polymers that undergo a dramatic conformational change from a tightly coiled form at neutral pH to an extended helical spiral at acidic pH. R-bodies were found in bacterial endosymbionts of paramecia, where their forceful extension causes vacuolar membranes to rupture contributing to a type of inter-paramecium warfare (Pond et al., 1989). Previous work has shown that R-body extension is fast, reversible, extremely robust, and tunable by directed evolution (Polka & Silver, 2016). However, it remains unknown how micron-scale changes in the conformation of an R-body ribbon arise from pH-induced changes in its nanoscale subunits. Here we use an interdisciplinary approach combining DIC microscopy, cryo-electron microscopy, atomic force microscopy, and hydrogen deuterium exchange to study individual, purified R-bodies in vitro. We show that R-body extension and contraction are highly cooperative and hysteretic processes with changes in the magnitude and direction of ribbon curvature as well as changes in ribbon thickness. Viewed en face, the R-body ribbon is a two-dimensional quasi-crystalline lattice with very small unit-cell dimensions (11.5 x 14.3 Å) that do not change with pH. Viewed edge-on, the ribbon has a laminar structure with five layers at neutral pH, two of which become indistinct at acidic pH. We show that the C-termini of the main constituent helical proteins, Reb A and Reb B, undergo large pH-dependent changes in accessibility for hydrogen-deuterium exchange, implying a transition from disordered at neutral pH to ordered helices at acidic pH. We propose this disordered-to-helical transition in the C-termini of Reb A and Reb B alters the tension within the concave side of the ribbon, driving changes in the local curvature of the ribbon to cause the extension process. Our findings provide a basis for understanding the mechanism of R-body extension, which may guide efforts to engineer R-bodies for novel drug delivery applications or to design new dynamic protein arrays.
- 일반주제명
- Biochemistry.
- 일반주제명
- Biophysics.
- 일반주제명
- Cellular biology.
- 일반주제명
- Molecular chemistry.
- 키워드
- pH responsive
- 키워드
- Protein arrays
- 기타저자
- University of Washington Biochemistry
- 기본자료저록
- Dissertations Abstracts International. 85-01B.
- 기본자료저록
- Dissertation Abstract International
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■00520240214101226
■006m o d
■007cr#unu||||||||
■020 ▼a9798379908553
■035 ▼a(MiAaPQ)AAI30527047
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a574
■1001 ▼aCai, Guangyang.
■24513▼aAn Interdisciplinary Investigation of Conformational Changes in Quasi-Crystalline Protein Array R-Bodies in Response to pH▼h[electronic resource]
■260 ▼a[S.l.]:▼bUniversity of Washington. ▼c2023
■260 1▼aAnn Arbor :▼bProQuest Dissertations & Theses, ▼c2023
■300 ▼a1 online resource(72 p.)
■500 ▼aSource: Dissertations Abstracts International, Volume: 85-01, Section: B.
■500 ▼aAdvisor: Kollman, Justin M.;Asbury, Charles A.
■5021 ▼aThesis (Ph.D.)--University of Washington, 2023.
■506 ▼aThis item must not be sold to any third party vendors.
■520 ▼aR-bodies are ribbon-like protein polymers that undergo a dramatic conformational change from a tightly coiled form at neutral pH to an extended helical spiral at acidic pH. R-bodies were found in bacterial endosymbionts of paramecia, where their forceful extension causes vacuolar membranes to rupture contributing to a type of inter-paramecium warfare (Pond et al., 1989). Previous work has shown that R-body extension is fast, reversible, extremely robust, and tunable by directed evolution (Polka & Silver, 2016). However, it remains unknown how micron-scale changes in the conformation of an R-body ribbon arise from pH-induced changes in its nanoscale subunits. Here we use an interdisciplinary approach combining DIC microscopy, cryo-electron microscopy, atomic force microscopy, and hydrogen deuterium exchange to study individual, purified R-bodies in vitro. We show that R-body extension and contraction are highly cooperative and hysteretic processes with changes in the magnitude and direction of ribbon curvature as well as changes in ribbon thickness. Viewed en face, the R-body ribbon is a two-dimensional quasi-crystalline lattice with very small unit-cell dimensions (11.5 x 14.3 Å) that do not change with pH. Viewed edge-on, the ribbon has a laminar structure with five layers at neutral pH, two of which become indistinct at acidic pH. We show that the C-termini of the main constituent helical proteins, Reb A and Reb B, undergo large pH-dependent changes in accessibility for hydrogen-deuterium exchange, implying a transition from disordered at neutral pH to ordered helices at acidic pH. We propose this disordered-to-helical transition in the C-termini of Reb A and Reb B alters the tension within the concave side of the ribbon, driving changes in the local curvature of the ribbon to cause the extension process. Our findings provide a basis for understanding the mechanism of R-body extension, which may guide efforts to engineer R-bodies for novel drug delivery applications or to design new dynamic protein arrays.
■590 ▼aSchool code: 0250.
■650 4▼aBiochemistry.
■650 4▼aBiophysics.
■650 4▼aCellular biology.
■650 4▼aMolecular chemistry.
■653 ▼aMembrane disruption
■653 ▼apH responsive
■653 ▼aProtein arrays
■653 ▼aRefractile bodies
■690 ▼a0487
■690 ▼a0786
■690 ▼a0379
■690 ▼a0431
■71020▼aUniversity of Washington▼bBiochemistry.
■7730 ▼tDissertations Abstracts International▼g85-01B.
■773 ▼tDissertation Abstract International
■790 ▼a0250
■791 ▼aPh.D.
■792 ▼a2023
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T16933275▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
■980 ▼a202402▼f2024
