       Document 0251
 DOCN  M9620251
 TI    In vitro activity of minimised hammerhead ribozymes.
 DT    9602
 AU    Hendry P; McCall MJ; Santiago FS; Jennings PA; CSIRO, Division of
       Biomolecular Engineering, North Ryde, NSW,; Australia.
 SO    Nucleic Acids Res. 1995 Oct 11;23(19):3922-7. Unique Identifier :
       AIDSLINE MED/96038849
 AB    A number of minimised hammerhead ribozymes (minizymes) which lack stem
       II have been kinetically characterised. These minizymes display optimal
       cleavage activity at temperatures around 37 degrees C. The cleavage
       reactions of the minizymes are first order in hydroxide ion
       concentration up to around pH 9.3 above which the cleavage rate
       constants decline rapidly. The reactions show a biphasic dependence on
       magnesium-ion concentration; one of the interactions has an apparent
       dissociation constant of around 20 mM while the other appears to be very
       weak, showing no sign of saturation at 200 mM MgCl2. The minizymes are
       significantly less active than comparable, full-size ribozymes when
       cleaving short substrates. However, at a particular site in a
       transcribed TAT gene from HIV-1, minizymes are more effective than
       ribozymes.
 DE    Animal  Base Sequence  Comparative Study  Drosophila
       melanogaster/GENETICS  DNA-Binding Proteins/GENETICS  Genes, tat
       Hydrogen-Ion Concentration  HIV-1/GENETICS  Kinetics
       Magnesium/PHARMACOLOGY  Molecular Sequence Data  Nucleic Acid
       Conformation  Rats  RNA, Catalytic/CHEMISTRY/*METABOLISM  RNA,
       Messenger/CHEMISTRY/METABOLISM  Somatotropin/GENETICS  Substrate
       Specificity  Temperature  Transcription Factors/GENETICS  JOURNAL
       ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

