Diets rich in linoleic acid (CO) from corn oil, or in linoleic acid and either alpha-linolenic acid (LO) based on linseed oil or n-3 fatty acids (MO) from menhaden oil were fed to male and female Cynomolgus monkeys for 15 wk. In the liver a 40% reduction of alpha-tocopherol occurred in the MO group relative to the CO and LO groups followed by increased formation of lipofuscin in vivo. A four-fold increase of alpha-tocopherol in the MO diet (MO + E) brought the level in the liver to that found with CO and LO. The increased peroxidation in the MO group in the liver phospholipids was associated with the replacement of 60% of the n-6 fatty acids by n-3 fatty acids from menhaden oil. Similar fatty acid profiles were found in groups fed MO and MO + E, respectively. Compared to the CO fed group, feeding alpha-linolenic acid only resulted in a slight incorporation of n-3 fatty acids in the liver membranes mainly due to a direct incorporation of alpha-linolenic acid. However, in monkeys fed menhaden oil more than 30% of the total fatty acids in the liver phospholipids were n-3 fatty acids. The various diets did not influence the activity of liver catalase (EC 1.11.1.6) nor superoxide dismutase (EC 1.15.1.1), but glutathione-peroxidase activity (EC 1.11.1.9) was higher in monkeys fed the MO diet. The catalase activity in females was 20% higher than in males.(ABSTRACT TRUNCATED AT 250 WORDS)

PDB References: -amylase complexed with acarbose and maltose, 2gjp, r2gjpsf; uncomplexed, 2gjr, r2gjrsf.Recombinant Bacillus halmapalus -amylase (BHA) was studied in two different crystal forms. The first crystal form was obtained by crystallization of BHA at room temperature in the presence of acarbose and maltose; data were collected at cryogenic temperature to a resolution of 1.9 Å . It was found that the crystal belonged to space group P2 1 2 1 2 1 , with unit-cell parameters a = 47.0, b = 73.5, c = 151.1 Å . A maltose molecule was observed and found to bind to BHA and previous reports of the binding of a nonasaccharide were confirmed. The second crystal form was obtained by pH-induced crystallization of BHA in a MES-HEPES-boric acid buffer (MHB buffer) at 303 K; the solubility of BHA in MHB has a retrograde temperature dependency and crystallization of BHA was only possible by raising the temperature to at least 298 K. Data were collected at cryogenic temperature to a resolution of 2.0 Å . The crystal belonged to space group P2 1 2 1 2 1 , with unit-cell parameters a = 38.6, b = 59.0, c = 209.8 Å . The structure was solved using molecular replacement. The maltose-binding site is described and the two structures are compared. No significant changes were seen in the structure upon binding of the substrates.

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Chelators are a common ingredient in most laundry detergents. They have a number of different functions such as reducing water hardness, assisting in keeping particulate soil in suspension and the removal of certain stains, thus complementing the action of the anionic surfactants. Another important group of components in a modern liquid detergent is enzymes, mainly proteases and amylases. As the most commonly used enzymes within the detergent industry are dependent on bound calcium ions to maintain conformational stability and function, the presence of both chelators and enzymes in a liquid detergent presents a challenge. The three commonly used Ca2+ chelators: citrate, DTPA (diethylene triamine pentaacetic acid) and HEDP (1‐hydroxyethane‐1,1‐diyl)bis(phosphonic acid), were studied with regard to their impact on protease and amylase stability in buffer and in a model liquid detergent. Enzyme stability was characterized by differential scanning calorimetry (DSC) and activity studies, and correlated to the chelator‐Ca2+ interaction properties. The results show that a chelator's ability to reduce water hardness and its Ca2+ affinity are in reality two separate aspects in the context of their use in liquid detergents. In the presence of DTPA, stoichiometric surplus of free Ca2+ is required to maintain sufficient amylase and protease stability. In the presence of the weaker chelators, HEDP and citrate, the total Ca2+ concentration is more important to protein stability than stoichiometric balancing between chelator and Ca2+. Thus, for these chelators their total concentration only has a minor impact on the Ca2+ concentration required to maintain or improve enzyme storage stability. The results underline the importance of Ca2+ in liquid detergent formulations, and suggest how proper balancing of chelators and Ca2+ can be used to improve overall enzyme stability.