Wyniki wyszukiwania

1

Construction and optimisation of a computer model for a bacterial membrane

100%

Murzyn K., Pasenkiewicz-Gierula M.

Acta Biochimica Polonica

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1999

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tom 46

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nr 3

The main steps in the construction of a computer model for a bacterial membrane are described. The membrane has been built of 72 lipid molecules, 54 of which being 1-palmitoyl-2-oleoyl-sn-glycerol-3-phosphatidylethanolamine (POPE) and 18 - 1-palmitoyl-2-oleoyl-sn-glycerol-3-phosphatidyl-rac-glycerol (POPG) molecules (thus in the proportion of 3:1). The membrane was hydrated with 1955 water molecules (approximately 27 water molecules per lipid). To neutralise the electronic charge (-e) on each POPG molecule, 18 sodium ions (Na+) were added to the membrane close to the POPG phosphate groups. The atomic charges on the POPE and POPG headgroups were obtained from ab initio quantum mechanical restrained electrostatic potential fitting (RESP) (Bayly et al., 1993, J. Phys. Chem. 97, 10269) using the GAMESS program at the 6-31G* level (Schmidt et al., 1993, J. Comput. Chem. 14, 1347). The model constructed in this way provided an initial structure for subsequent molecular dynamics simulation studies intended to elucidate the atomic level interactions responsible for the structure and dynamics of the bacterial membrane.

2

Molecular dynamics simulation studies of lipid bilayer systems

80%

Pasenkiewicz-Gierula M., Murzyn K., Rog T., Czaplewski C.

Acta Biochimica Polonica

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2000

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tom 47

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nr 3

The main structural element of biological membranes is a liquid-crystalline lipid bilayer. Other constituents, i.e. proteins, sterols and peptides, either intercalate into or loosely attach to the bilayer. We applied a molecular dynamics simulation method to study membrane systems at various levels of compositional complexity. The studies were started from simple lipid bilayers containing a single type phosphatidylcholine (PC) and water molecules (PC bilayers). As a next step, cholesterol (Chol) molecules were introduced to the PC bilayers (PC-Chol bilayers). These studies provided detailed information about the structure and dynamics of the membrane/water interface and the hydrocarbon chain region in bilayers built of various types of PCs and Chol. This enabled studies of membrane systems of higher complexity. They included the investigation of an integral membrane protein in its natural environment of a PC bilayer, and the antibacterial activity of magainin-2. The latter study required the construction of a model bacterial membrane which consisted of two types of phospholipids and counter ions. Whenever published experimental data were available, the results of the simulations were compared with them.

3

Methylobacterium extorquens strain P14, a new methylotrophic bacteria producing poly-beta-hydroxybutyrate [PHB]

80%

Ostafin M., Haber J., Doronina N. V., Sokolov A. P., Trotsenko J. A.

Acta Microbiologica Polonica

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1999

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tom 48

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nr 1

4

Effects of pH and detergents on galactolipase activity in chloroplast of chilling-sensitive and chilling-resistant plants

61%

Saczynska V., Miskiewicz E., Kaniuga Z.

Acta Physiologiae Plantarum

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1994

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tom 16

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nr 4

Ograniczanie wyników

2 Acta Biochimica Polonica

1 Acta Microbiologica Polonica

1 Acta Physiologiae Plantarum

2 Murzyn K.

2 Pasenkiewicz-Gierula M.

1 Czaplewski C.

1 Doronina N. V.

1 Haber J.

1 Kaniuga Z.

1 Miskiewicz E.

1 Ostafin M.

1 Rog T.

1 Saczynska V.

1 Sokolov A. P.

1 Trotsenko J. A.

1 2000

2 1999

1 1994

Construction and optimisation of a computer model for a bacterial membrane

Molecular dynamics simulation studies of lipid bilayer systems

Methylobacterium extorquens strain P14, a new methylotrophic bacteria producing poly-beta-hydroxybutyrate [PHB]

Effects of pH and detergents on galactolipase activity in chloroplast of chilling-sensitive and chilling-resistant plants