{"created":"2021-03-01T06:22:14.975589+00:00","id":5550,"links":{},"metadata":{"_buckets":{"deposit":"6edcb26f-4051-4504-ac8f-226efeaa6c66"},"_deposit":{"id":"5550","owners":[],"pid":{"revision_id":0,"type":"depid","value":"5550"},"status":"published"},"_oai":{"id":"oai:repository.dl.itc.u-tokyo.ac.jp:00005550","sets":["27:123:367","9:233:280"]},"item_7_alternative_title_1":{"attribute_name":"その他のタイトル","attribute_value_mlt":[{"subitem_alternative_title":"魚介類トロポミオシンの構造安定性に関する研究"}]},"item_7_biblio_info_7":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"2012-03-22","bibliographicIssueDateType":"Issued"},"bibliographic_titles":[{}]}]},"item_7_date_granted_25":{"attribute_name":"学位授与年月日","attribute_value_mlt":[{"subitem_dategranted":"2012-03-22"}]},"item_7_degree_grantor_23":{"attribute_name":"学位授与機関","attribute_value_mlt":[{"subitem_degreegrantor":[{"subitem_degreegrantor_name":"University of Tokyo (東京大学)"}]}]},"item_7_degree_name_20":{"attribute_name":"学位名","attribute_value_mlt":[{"subitem_degreename":"博士(農学)"}]},"item_7_description_5":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"The amino acid sequences of tropomyosins (TMs) have been determined for many species: Atlantic salmon Salmo salar (Heeley et al., 1995), bluefin tuna Tunnus tuna (Huang et al., 2004; Ochiai et al., 2010), kuruma prawn Marsupenaeus japonicas (Motoyama et al., 2007), mussel Mytilus edulis galloprovincialis (Iwasaki et al., 1997), rabbit Oryctolagus cuniculus (Stone and Smillie, 1978; Mak et al., 1979), tokobushi abalone Haliotis diversicolor (Chu et al., 2000), torafugu Takifugu rubripes (Ikeda et al., 2003), white croaker Pennahia argentata (Ochiai et al., 2001), walleye pollack Theragra chalcogramma (Ochiai et al., 2003), Yesso scallop Mizuhopecten yessoensis (Hasegawa, 2001), and zebrafish Danio rerio (Ohara et al., 1989). Invertebrate TMs are known as allergens and show higher viscosity than fish TMs, but the basic characteristics, in view of the comparative biochemistry, have not been studied so much. Elucidation of the relationship between amino acid sequence and stability would contribute to ascertain above interesting invertebrate TM properties. But the stability of invertebrate TM has been rarely measured (Inoue et al., 2004). The stability of TMs from fish (Huang and Ochiai, 2005) was estimated by differential scanning calorimetry (DSC) and it has been shown that fish TM, as rabbit TM (Potekhin and Privalov 1982), contains a few unfolding units. Thus, it would be adequate to measure the thermal stability of peptides or fragments. In Chapter 1, the stability of invertebrate TMs was investigated. TMs from the tail muscle of kuruma prawn, mantle muscle of Japanese common squid Todarodes pacificus, foot muscle of tokobushi abalone, and striated and smooth adductor muscles of Yesso scallop were purified and these stabilities were determined by circular dichroism (CD) spectrometry and DSC. The white croaker TM was used as control. In addition, three mRNAs encoding the smooth muscle TMs of the scallop have been sequenced (Hasegawa, 2001) and the major component was determined at the protein level. CD spectrometry and DSC have suggested that the thermal stability is in the order of prawn TM > abalone TM > squid TM ≒ white croaker TM > scallop smooth muscle TM > scallop striated muscle TM. The stability difference between scallop TMs and other TMs reflected the habitat temperature, but the stability difference between scallop striated and smooth muscle TMs could come from other physiological demands. The striated muscle expedites jet water propulsion for quick locomotion, while the smooth muscle can keep the shell closed by maintaining large tension with little energy expenditure for a long time (so-called catch condition). Therefore, the protein components are considered to have different profiles between the two muscles. In Chapter 2, five synthetic peptides of 30mer were designed, based on the sequence of walleye pollack fast muscle TM: Peptide Nterm (Met1-Lys30) which consisted of N-terminal region, Peptide Var (Asp84-Leu113) which consisted of the variable region, Peptide Mid (Val128-Ala157) which consisted of the middle region of TM, Peptide Cys (Leu176-Lys205) which contained the conserved Cys190 residue, and Peptide Cterm (Asp255-Ile284) which consisted of C-terminal region. The thermal stabilities of these peptides were determined by CD spectrometry in the presence and absence of 40% 2, 2, 2-trifluoroethanol (TFE). In 40% TFE, the helical contents of these peptides were decreased, as temperature rose, though they showed no clear melting temperature, suggesting that the enthalpy necessary for transition from the highly α-helical conformation to the highly random coil containing conformation of each peptide was low. The calculation by AGADIR, α-helical content prediction software for the monomeric peptides, showed good accordance with the measured α-helical contents of all peptides in the absence of TFE, except for Peptide Cterm. In addition, the α-helical contents did not show concentration dependence in 40% TFE. Thus, all peptides, except for Peptide Cterm, would not have coiled-coil interaction under these experimental conditions. These results suggested that the stability was in the order of Peptide Cterm > Peptide Var > Peptide Nterm ≒ Peptide Mid ≒ Peptide Cys. The higher stability of Peptide Cterm could be important for the head-to-tail interaction between N and C terminal regions. In Chapter 3, white croaker TM was cleaved by 2-nitro-5-thiocyanatobenzoic acid (NTCB). At the 190th residue, fish TM has only one conserved cysteine residue, where NTCB cleaves the peptide bond. Fragments produced by NTCB were purified and measured by CD spectrometry. From CD data, C-terminal fragment (Cys190-Ile284) showed higher stability than N-terminal fragment (Met1-Lys189), regardless of its shorter length. It has been reported that the rabbit TM C-terminal fragment shows lower stability than the N-terminal fragment and low stability of the C-terminal fragment is discussed with the interaction with troponin. Thus, the present study suggests that such idea should be reconsidered. In Chapter 4, molecular dynamics simulations for the rabbit and white croaker TM C-terminal fragments were performed by Amber10. These fragments (rabbit/white croaker) contain four amino acid substitutions (Ala/Ser191, Ser/Thr229, Thr/Ala247, and Ser/Thr252). The study in this chapter indicates that the substitution at the 229th residue stabilizes rabbit TM fragment, while the substitutions at the 247th and/or 252nd residue stabilize the white croaker TM fragment. In Chapter 5, general discussion was performed, based on the results of the present study to make clear what was established for invertebrate and vertebrate TMs so far and to scope further investigations.","subitem_description_type":"Abstract"}]},"item_7_dissertation_number_26":{"attribute_name":"学位授与番号","attribute_value_mlt":[{"subitem_dissertationnumber":"甲第28073号"}]},"item_7_full_name_3":{"attribute_name":"著者別名","attribute_value_mlt":[{"nameIdentifiers":[{"nameIdentifier":"11558","nameIdentifierScheme":"WEKO"}],"names":[{"name":"小澤, 秀夫"}]}]},"item_7_identifier_registration":{"attribute_name":"ID登録","attribute_value_mlt":[{"subitem_identifier_reg_text":"10.15083/00005541","subitem_identifier_reg_type":"JaLC"}]},"item_7_select_21":{"attribute_name":"学位","attribute_value_mlt":[{"subitem_select_item":"doctoral"}]},"item_7_subject_13":{"attribute_name":"日本十進分類法","attribute_value_mlt":[{"subitem_subject":"487","subitem_subject_scheme":"NDC"}]},"item_7_text_22":{"attribute_name":"学位分野","attribute_value_mlt":[{"subitem_text_value":"Agriculture (農学)"}]},"item_7_text_24":{"attribute_name":"研究科・専攻","attribute_value_mlt":[{"subitem_text_value":"Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences (農学生命科学研究科水圏生物科学専攻)"}]},"item_7_text_27":{"attribute_name":"学位記番号","attribute_value_mlt":[{"subitem_text_value":"博農第3789号"}]},"item_7_text_4":{"attribute_name":"著者所属","attribute_value_mlt":[{"subitem_text_value":"東京大学大学院農学生命科学研究科水圏生物科学専攻"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"Ozawa, Hideo"}],"nameIdentifiers":[{"nameIdentifier":"11557","nameIdentifierScheme":"WEKO"}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2017-06-01"}],"displaytype":"detail","filename":"39-097064.pdf","filesize":[{"value":"3.1 MB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"39-097064.pdf","url":"https://repository.dl.itc.u-tokyo.ac.jp/record/5550/files/39-097064.pdf"},"version_id":"7cf6316a-7b13-4d65-8456-b2275f831e1b"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"eng"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"thesis","resourceuri":"http://purl.org/coar/resource_type/c_46ec"}]},"item_title":"Studies on the structural stability of tropomyosins from fish and marine invertebrates","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Studies on the structural stability of tropomyosins from fish and marine invertebrates"}]},"item_type_id":"7","owner":"1","path":["280","367"],"pubdate":{"attribute_name":"公開日","attribute_value":"2014-02-24"},"publish_date":"2014-02-24","publish_status":"0","recid":"5550","relation_version_is_last":true,"title":["Studies on the structural stability of tropomyosins from fish and marine invertebrates"],"weko_creator_id":"1","weko_shared_id":null},"updated":"2022-12-19T03:47:08.566332+00:00"}