A comparative study for the intermediate states of myelin oligodendrocyte glycoprotein in the absence and presence of glycan - A computational approach.

Myelin Oligodendrocyte glycoprotein (MOG) is found to play an important role in providing structural integrity to myelin sheath at the same time it acts as an auto-antigen which might lead to Multiple Sclerosis (MS). What causes this specific property of being an auto-antigen is still not known. Here we present molecular dynamics simulation studies of unfolding and folding of the protein MOG in both the absence and presence of N-glycan in order to understand the role of glycosylation in the stability and flexibility of the protein.

Cloning, expression, crystallization and preliminary X-ray crystallographic analysis of aspartyl aminopeptidase from the apeB gene of Pseudomonas aeruginosa. Retraction.

The article by Natarajan & Mathews [(2012) Acta Cryst. F68, 207–210] is retracted.

4-Amino-3-(4-chloro-phen-yl)-1H-1,2,4-triazole-5(4H)-thione.

In the title compound, C(8)H(7)ClN(4)S, the benzene ring is statistically disordered over two conformations rotated about the Cl-C⋯C-C axis, which subtend dihedral angles of 24.7 (3) and 9.9 (2) ° with respect to the triazole ring.

(Z)-2-[(4-Methyl-phen-yl)sulfon-yl]-1,2-diphenyl-ethene-selenol.

In the title compound, C(21)H(18)O(2)SSe, the dihedral angle between the cis phenyl rings is 64.3 (1)° and those between the toluene and the phenyl rings are 21.1 (2) and 72.

1'-Methyl-4'-phenyl-2''-sulfanylidene-dispiro-[indoline-3,2'-pyrrolidine-3',5''-1,3-thia-zolidine]-2,4''-dione.

The title compound, C(20)H(17)N(3)O(2)S(2), crystallizes with two mol-ecules in the asymmetric unit. The pyrrolo-dine rings have envelope conformations in both mol-ecules, the N atoms deviating by 0.574 (3) and 0.

Cloning, expression, crystallization and preliminary X-ray crystallographic analysis of aspartyl aminopeptidase from the apeB gene of Pseudomonas aeruginosa.

Aminopeptidases (APs) are a group of exopeptidases that catalyze the removal of amino acids from the N-termini of proteins and peptides. The APs are ubiquitous in nature and are of critical biological and medical importance because of their key role in protein degradation. Pseudomonas aeruginosa aspartyl aminopeptidase (PaAAP), which is encoded by the apeB gene, was expressed in Escherichia coli, purified and crystallized using the microbatch method.

4-({(E)-[2-(But-3-en-1-yl)-1-(prop-2-en-1-yl)-4-sulfanyl-1H-imidazol-5-yl]methyl-idene}amino)-3-phenyl-1H-1,2,4-triazole-5(4H)-thione.

In the title compound, C(19)H(20)N(6)S(2), the dihedral angle between the phenyl and triazole rings is 24.1 (2)° while the dihedral angles between the imidazole ring and the triazole and phenyl rings are 39.9 (2) and 55.

2,4-Diamino-5-(4-chloro-phen-yl)-6-ethyl-pyrimidin-1-ium 2-propanamido-benzoate.

In the title salt, C(12)H(14)ClN(4) (+)·C(10)H(10)NO(3) (-), zwitterionic N-H⋯O inter-actions form an R(2) (2)(8) ring. The crystal structure is stabilized by N-H⋯O and N-H⋯N hydrogen bonds involving two different eight-membered rings. An N-H⋯O inter-action occurs between the pyrimidine ring (donor) and carboxyl-ate group (acceptor) while the other ring is formed by N-H⋯N inter-actions, which form a dimer between two symmetry-related salts.

2,4-Diamino-5-(4-chloro-phen-yl)-6-ethyl-pyrimidin-1-ium 2-acet-amido-benzoate.

The title compound, C(12)H(14)ClN(4) (+)·C(9)H(8)NO(3) (-), is a salt with a 1:1 ratio of cation and anion components inter-acting with each other forming an R(2) (2)(8) ring motif. The crystal structure is stabilized by hydrogen bonds (N-H⋯O) involving two different eight-membered rings. One of them is formed between the pyrimidine ring (donor) and the carboxylate group (acceptor) from the benzoate, whereas the other ring is formed by N-H⋯O interactions, which help to form a dimer between two symmetry-related salts in the unit cell.

3-Nitroso-2,4,6,8-tetra-phenyl-3,7-diaza-bicyclo-[3.3.1]nonan-9-one.

In the title compound, C(31)H(27)N(3)O(2), the two piperidine rings fused to each other each adopt a slightly distorted chair conformation. The phenyl rings on the N-unsubstituted piperidine ring occupy an equatorial position, while those on the N-nitroso-substituted piperidine ring are in axial positions. The NO group is approximately coplanar with the piperidine ring with a maximum deviation of 0.

Ethyl 3-methyl-2,6-diphenyl-piperidine-1-carboxyl-ate.

In the title compound, C(21)H(25)NO(2), the piperidine ring adopts a twisted boat conformation characterized by puckering parameters θ = 89.5 (1) and ϕ = 257.5 (2)°.