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Analysis of Human Transfer RNA Gene Heteroclusters

Description: Two phage lambda clones encompassing human tRNA genes have been isolated from a human gene library harbored in bacteriophage lambda Charon-UA. One of the clones (designated as hLeuU) containing a 20-kb human DNA fragment was isolated and found to contain a cluster of four tRNA genes. An 8.2-kb Hindlll fragment encompassing the four tRNA genes was isolated from the 20-kb fragment and subcloned into pBR322 for restriction mapping and DNA sequence analysis. The four tRNA genes are arranged as two… more
Date: December 1986
Creator: Chang, Yung-Nien
open access

Mechanism of the Adenosine 3',5'-Monophosphate Dependent Protein Kinase

Description: Isotope partitioning experiments were carried out with the adenosine 3',5'-monophosphate-dependent protein kinase catalytic subunit (cAPK) from bovine hearts to obtain information on the order of addition of reactants and the relative rates of reactant release from enzyme compared to the catalytic step(s). A value of 100% trapping for both ErMgATP-[γ-32P] and E:3H-Serpeptide at low Mgf indicates that MgATP and Serpeptide dissociate slowly from the enzyme compared to the catalytic step(s). The K… more
Date: May 1988
Creator: Kong, Cheng-Te
open access

Metabolism of Diadenosine-5ʹ,5ʹʹʹ-P¹,P⁴-tetraphosphate (Ap₄A) in Cultured Mammalian Cells

Description: Methodology was developed which allowed the rapid and routine quantitation of subpicomole quantities of diadenosine-5ʹ,5ʹʹʹ-P¹,P⁴-tetraphosphate (Ap₄A) in cultured mammalian cells. This methodology includes the rapid extraction of cellular nucleotides in cold alkali, resolution of Ap₄A from the bulk of cellular materials on a highly specific boronate affinity resin, and quantitation of the dinucleotide in a coupled bioluminescence assay utilizing venom phosphodiesterase and firefly luciferase. … more
Date: December 1984
Creator: Baker, Jeffrey C. (Jeffrey Clayton)
open access

Posttranslational Modification of Proteins by ADP-ribosylation

Description: This work presents the development of a highly sensitive and selective chemical assay for mono(ADP-ribose) residues covalently bound to proteins in vivo. An extensive review of the literature is presented in the introduction of this work. The physiological.functions of mono(ADP-ribosyl)transferase activities associated with certain bacterial toxins (e.g., diphtheria, cholera and pertussis toxins) are well established. However, the roles of endogenous vertebrate transferases are unknown. The elu… more
Date: December 1984
Creator: Payne, David M. (David Michael)
open access

Studies of Enzyme Mechanism Using Isotopic Probes

Description: The isotope partitioning studies of the Ascaris suum NAD-malic enzyme reaction were examined with five transitory complexes including E:NAD, E:NAD:Mg, E:malate, E:Mg:malate, and E:NAD:malate. Three productive complexes, E:NAD, E:NAD:Mg, and E:Mg:malate, were obtained, suggesting a steady-state random mechanism. Data for trapping with E:14C-NAD indicate a rapid equilibrium addition of Mg2+ prior to the addition of malate. Trapping with 14C-malate could only be obtained from the E:Mg2+:14C-malate… more
Date: August 1987
Creator: Chen, Cheau-Yun
open access

Studies on Hog Plasma Lecithin:cholesterol Acyltransferase: Isolation and Characterization of the Enzyme

Description: Lecithin:cholesterol acyltransferase (LCAT) was isolated from hog plasma and basic physicochemical properties and functionally important regions were investigated. Approximately one milligram of the enzyme was purified to apparent homogeneity with approximately a 20,000-fold increase in specific activity. In the plasma, hog LCAT was found to associate with high-density lipoproteins (HDL) probably through hydrophobic interactions with apolipoprotein A-I. HDL was the preferred lipoprotein substra… more
Date: May 1987
Creator: Park, Yong Bok
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