title: The roles of cosolutes on the hammerhead ribozyme activity.
abstract: The hammerhead ribozyme is often used for gene regulations in a cell. One of the major differences between in vitro and in cell conditions is the molecular crowding. However, the influence of crowding conditions on the ribozyme activity is still unclear. Here, we investigated the activity of the hammerhead ribozyme under molecular crowding condition by ethylene glycol (EG), poly (ethylene glycol) (PEG), dextran, and Ficoll. These cosolutes enhanced the hammerhead ribozyme activity by 2 to approximately 7-times, and larger-sized PEGs exhibited the greater activity. More importantly, the rate constant at 1 mM Mg(2+) and 37 degrees C increased about 1000-times and 500-times upon the addition of 20 wt% PEG8000 and PEG200, respectively. Additionally, the ribozyme still retained the cleavage activity even at 50 degrees C in the presence of PEG8000. Our results suggest that the ribozyme activity can be enhanced by the addition of the crowding reagent even at a low magnesium ion concentration and even at a high temperature.
authors.affiliation: Department of Chemistry, Faculty of Science and Engineering, Konan University, 8-9-1 Okamoto, Higashinada-ku, Kobe 658-8501, Japan.
authors.forename: Hisae
authors.initials: H
authors.lastname: Karimata
authors.forename: Shu-ichi
authors.initials: S
authors.lastname: Nakano
authors.forename: Naoki
authors.initials: N
authors.lastname: Sugimoto
mesh_terms: D003911:Dextrans / Q000737:chemistry; D019855:Ethylene Glycol / Q000737:chemistry; D005362:Ficoll / Q000737:chemistry; D008274:Magnesium / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D016337:RNA, Catalytic / Q000737:chemistry* / Q000378:metabolism; D013696:Temperature
chemical_list: D003911:Dextrans; D016337:RNA, Catalytic; C427204:hammerhead ribozyme; D005362:Ficoll; D011092:Polyethylene Glycols; D019855:Ethylene Glycol; D008274:Magnesium