生物化学技术

Spermidine and spermine syntheses carry out the transfer of aminopropyl groups from decarboxylated S-adenosylmethionine (dcAdoMet) to putrescine and spermidine, respectively. Despite the close similarity of these reactions, they are totally distinct enzymes. Spermidi ...

Diamine oxidase activity (E.C. 1.4.3.6) can be measured by a modification of the method first reported by Okuyama and Kobayashi (1), as developed by Trydingetal. (2–4). Oxidation of putrescine by diamine oxidase leads to the formation of γ--aminobutylaldehyde, which rapidly and spontaneou ...

Polyamine oxidases, defined in this chapter as amine oxidases capable of catalyzing the oxidation of spermidine or spermine (1,2) (see Chapter 1), are present in plants, bacteria, fungi, protozoa, worms, and all mammalian cells (2,3) (see references in Chapter 1). In mammalian cells spermine and ...

The polyamines spermine and spermidine can be metabolized by polyamine oxidases in two ways, oxidative determination or oxidative cleavage (1,2) (see Chapter 1). An example of the former is the amine oxidase present in bovine (and other ruminant) sera (3) that deaminates polyamines in accor ...

N 8-Acetylspermidine deacetylase is a cytoplasmic enzyme found in a wide variety of tissues in higher organisms (1). This enzyme catalyzes the deacetylation of polyamines N-acetylated on the terminal ammo group on the 4-carbon end of the molecule. Thus, N 8-acetylspermidine and N-acetylp ...

Amine oxidase activity can be assessed by measuring the conversion of substrate to product, or by measuring the formation of concomitantly formed hydrogen peroxide. Fluorometry offers greater sensitivity and selectivity than conventional calorimetric methods for measuring ...

Almost all of the methods available to analytical biochemists have been applied to polyamine analysis at some time. The diversity of the methods used is an indication of the difficulties experienced in attempts to measure the polyamine content of biological samples. The quantitation of po ...

The use of the fluorescent acid chloride 5-dimethylaminonaphthalene-1-sulfonylchloride (dansyl chloride) is particularly suited to the separation and quantitation of polyamines by chromatographic techniques. Both the primary and secondary amino groups of polyamines ...

The derivatization of polyamines and amino acids with fluorescamine is a useful tool for the detection and quantitation of these compounds. High-pressure liquid chromatography (HPLC) separation coupled to postcolumn derivatization allows for the detection of nanomole amoun ...

The naturally occurring polyamines putrescine, spermidine, and spermine are found in all tissues and microorganisms (1–5). Polyamines are cations that have been implicated in various growth processes and in cellular differentiation (6). This chapter describes a simple and rapid me ...

Most cells can take up polyamines, and some polyamine analogs, by a process that is independent of amino acid transport systems (1,2), and that, in certain circumstances, can substitute for synthesis de novo. In some cells polyamines are taken up by both saturable and nonsaturable systems. Uptake ...

The polyamines are cellular growth factors in most living organisms. Cells that are rapidly growing require high polyamine concentrations, whereas quiescent cells maintain comparatively low polyamine concentrations (1,2). This was shown to be the case in normal baby hamster kidney ...

Most cells are able to supplement de novo polyamine synthesis with uptake on specific transport systems, especially in response to stimuli that provoke cell growth or when de novo synthesis is blocked by specific inhibitors, such as D,L-α-difluoromethylornithine (1,2).

Although their precise role is poorly understood, polyamines appear to be important in cell growth. This is probably through their ready interaction with cell membrane components, nucleic acids, and proteins. One consequence of these interactions is that polyamines are able to modula ...

Free radicals and free radical-derived oxidants play important roles in biological systems and have been implicated in the pathology of many diseases. The major problem in determining the role of reactive oxygen species (ROS) has been that these short-lived species are difficult to measu ...

In the course of examining the effects on cells of polyamines, their metabolites, and polyamine analogs, it is often necessary to make some measure of cellular activity as an indicator of cell damage or cytotoxicity. One of the simplest assays utilizes 3--2,5-diphenyl tetrazolium bromide (MT ...

Histochemical reactions for lipid hydroperoxides (LHP) using indophenol, benzidine, or phenylendiamine as the electron donor have been described previously for auto-oxidized adipose (1) and neuronal (2) tissue. More recently, tetramethylbenzidine (TMB) has been proposed as ...

Glutathione peroxidase (GSH-PO), a selenium-dependent and lipid peroxide-scavenging enzyme that effectively reduces lipid peroxides with the concomitant oxidation of glutathione is distributed in mitochondria (1,2). Utsunomiya et al. (3) confirmed the dual localization of ...

In almost all aerobic cells, the oxygen metabolism generates reactive oxygen species (ROS), such as superoxide, hydroxyl radicals, and hydrogen peroxide. These ROS can peroxidize membrane lipids of a cell and its organelles, and can also attack DNA or protein (1). During the process of lipid per ...

The oxidative modification of proteins by reactive oxygen species (ROS) and other reactive compounds is associated with a number of disease and pathophysiological processes as well as aging (1). Under physiological conditions, almost all oxidative modifications of proteins are re ...