Since Hahn demonstrated the clearing of alimentary lipemia by the intravenous injection of heparin, many excellent studies have been done on lipoprotein lipase (LPL). In these studies, however, LPL activities were compared in normal and pathological conditions at a certain time after heparin injection. If the level of LPL activity in the circulating blood changes continuously after heparin inje...

The mechanism of the hexokinase reaction has been the subject of numerous investigations in recent years (l-5). ijgren and Engstrijm reported the incorporation of Pa from labeled adenosine triphosphate (ATP) into the phosphoserine moiety of hexokinase in the absence of substrate glucose and concluded that an enzyme-phosphate intermediate participated in the reaction (2). Gamble and Najjar, howe...

1. Bilirubin glucuronide was synthesized in vitro in a system containing a rat liver microsomal fraction, UDP-glucuronic acid, Mg2+ and bilirubin. The enzymic synthesis was accomplished without the addition of a bilirubin carrier. 2. Azobilirubin and azobilirubin glucuronide were separated by t.l.c. and paper chromatography and the measurement of the conjugate provided a specific asay for bilir...

Kinetic and mechanistic studies on some characteristic freeradica1 reactions are reviewed briefly. The unimolecular rearrangements: RCMe2CH ÷ Me2CCH2R, fall into two classes. Class 1: R = R'C(O)O for which the 1,2—migration occurs via a 5—eenter cyclic transition state with considerable charge separation, [R'C02 Me2CCH2]*. Class 2: R = H2C=CH, Me3CC=0, C6H5, Me3CCsC, and CsN, for which migratio...

Chapter 1. Principles of Small Molecule Activation by Metalloproteins as Exemplified by the Soluble Methane Monooxygenase Many metalloenzymes activate small molecules in a manner that is unique to natural systems. In this perspective we discuss the soluble protein system from Methylococcus capsulatus (Bath), which uses a mixed-function hydroxylase to convert methane selectively to methanol. Thr...

1. NADH2 prepared by enzymic reduction of pure NAD by the method of Rafter & Colowick (1957), and isolated as the sodium salt, gives higher maxrimum rates of reduction of acetaldehyde with liver alcohol dehydrogenase at pH 6 than a number of commercial preparations of high purity. Maximum values of 2-4 for the extinction ratio E260/E340 and 2% for the proportion of inactive material absorbing a...

The structure of a protein-protein interaction, its affinity and thermodynamic characteristics depict a 'frozen' state of a complex. This picture ignores the kinetic nature of complex formation and dissociation, which are of major biological and biophysical interest. This review highlights recent advances in deciphering the kinetic pathway of protein-protein complexation, the nature of the enco...

Arsenic mobility in pyrite ashes was studied because of the possible effects on water systems. The batch extraction method was used to assess kinetics and extent of As release induced by contact of the material either with rainwater or groundwater. Self-established pH-Eh range of pyrite ashes/water mixtures brought both As(III) and As(V) to be present in the water phase, as neutral arsenite H3A...

A microcomputer-interfaced data acquisition system for chemical kinetics (interfacing with laboratory analogue instruments) has been developed. Analogue signals from instruments used in kinetics experiments are amplifed by a wide-range adjustable high-gain operational amplifier and smoothed by an op-based filter, and then digitized at rates of up to 10(4) samples per channel by an ADC 0816 digi...

The activation of plasminogen by two novel hybrid enzymes, constructed from the A-chain of plasmin and the B-chains of tissue-type plasminogen activator (t-PA) or urokinase, was compared with the activation by the parent enzymes. Basal kinetic constants for 'Lys-plasminogen' (human plasminogen with N-terminal lysine) and 'Glu-plasminogen' (human plasminogen with N-terminal glutamic acid) activa...