DNA ligase from Drosophila melanogaster embryos. Substrate specificity and mechanism of action.

Dynamin, a 100 kDa GTPase, is essential for receptor mediated endocytosis and synaptic vesicle recycling; however its mechanism of action is unknown. The requirement for dynamin was first elucidated by the discovery that the shibire gene product in Drosophila melanogaster was homologous to mammalian dynamin-1 (1,2). The shibire flies exhibit a depletion of synaptic vesicles and an accumulation of collared clathrin-coated pits at the plasma membrane of their nerve termini (3). It was later demonstrated that endocytosis was inhibited by the overexpression of dominant negative mutants of dynamin (4,5), and that purified dynamin can self-associate to form spirals which resemble the collars of shibire and structures seen in synaptosomes treated with GTPγS (6,7). These observations led to the speculation that dynamin pinches the clathrin-coated bud from the plasma membrane. In support of this hypothesis, we show that purified recombinant dynamin can bind to a lipid bilayer in a regular and repeating pattern to form helical tubes which vesiculate upon the addition of GTP.

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Unexpected substrate specificity of T4 DNA ligase revealed byin vitroselection

Nucleic Acids Research ◽

10.1093/nar/21.10.2287 ◽

1993 ◽

Vol 21 (10) ◽

pp. 2287-2291 ◽

Cited By ~ 38

Author(s):

Kazuo Harada ◽

Leslie E. Orgel

Keyword(s):

Substrate Specificity ◽

Dna Ligase ◽

T4 Dna Ligase

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Aldehyde Dehydrogenase Inhibitors: a Comprehensive Review of the Pharmacology, Mechanism of Action, Substrate Specificity, and Clinical Application

Pharmacological Reviews ◽

10.1124/pr.111.005538 ◽

2012 ◽

Vol 64 (3) ◽

pp. 520-539 ◽

Cited By ~ 262

Author(s):

Vindhya Koppaka ◽

David C. Thompson ◽

Ying Chen ◽

Manuel Ellermann ◽

Kyriacos C. Nicolaou ◽

...

Keyword(s):

Substrate Specificity ◽

Clinical Application ◽

Aldehyde Dehydrogenase ◽

Mechanism Of Action ◽

Comprehensive Review

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Brain histone kinase: The structure, the substrate specificity and the mechanism of action

Advances in Enzyme Regulation ◽

10.1016/0065-2571(76)90024-8 ◽

1976 ◽

Vol 14 ◽

pp. 407-444 ◽

Cited By ~ 8

Author(s):

E.S. Severin ◽

M.V. Nesterova ◽

N.N. Gulyaev ◽

S.V. Shlyapnikov

Keyword(s):

Substrate Specificity ◽

Mechanism Of Action ◽

Histone Kinase

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Properties of Chlorophyllase from Capsicum annuum L. Fruits

Zeitschrift für Naturforschung C ◽

10.1515/znc-2001-11-1219 ◽

2001 ◽

Vol 56 (11-12) ◽

pp. 1015-1021 ◽

Cited By ~ 7

Author(s):

Dámaso Hornero-Méndez ◽

María Isabel Mínguez-Mosquera

Keyword(s):

Substrate Specificity ◽

Capsicum Annuum ◽

Mechanism Of Action ◽

Substrate Recognition ◽

Substrate Inhibition ◽

Inhibitory Effect ◽

Hplc Separation ◽

Substrate Complex ◽

Enzyme Substrate

Abstract The in vitro properties of semi-purified chlorophyllase (chlorophyll-chlorophyllido hydrolase, EC 3.1.1.14) from Capsicum annuum fruits have been studied. The enzym e showed an optimum of activity at pH 8.5 and 50 °C. Substrate specificity was studied for chlorophyll (Chi) a, Chi b, pheophytin (Phe) a and Phe b, with Km values of 10.70, 4.04, 2.67 and 6.37 μᴍ respectively. Substrate inhibition was found for Phe b at concentrations higher than 5 μᴍ. Chlorophyllase action on Chi a' and Chi b' was also studied but no hydrolysis was observed, suggesting that the mechanism of action depends on the configuration at C-132 in the chloro phyll molecule, with the enzyme acting only on compounds with R132 stereochemistry. The effect of various metals (Mg2+, Hg2+, Cu2+, Zn2+, Co , Fe2+ and Fe3+) was also investigated, and a general inhibitory effect was found, this being more marked for Hg2+ and Fe2+. Functional groups such as -SH and -S-S-seem ed to participate in the formation o f the enzyme-substrate complex. Chelating ion and the carbonyl group at C3 appeared to be important in substrate recognition by the enzyme. The method for measuring Chlase activity, including HPLC separation of substrate and product, has been optimized.

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