抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

J. Appl. Cryst.の発刊に際して

The Carbohydrate-Active Enzymes database (CAZy; http://www.cazy.org) provides online and continuously updated access to a sequence-based family classification linking the sequence to the specificity and 3D structure of the enzymes that assemble, modify and breakdown oligo- and polysaccharides. Functional and 3D structural information is added and curated on a regular basis based on the available literature. In addition to the use of the database by enzymologists seeking curated information on CAZymes, the dissemination of a stable nomenclature for these enzymes is probably a major contribution of CAZy. The past few years have seen the expansion of the CAZy classification scheme to new families, the development of subfamilies in several families and the power of CAZy for the analysis of genomes and metagenomes. This article outlines the changes that have occurred in CAZy during the past 5 years and presents our novel effort to display the resolution and the carbohydrate ligands in crystallographic complexes of CAZymes.

/pdf/the-carbohydrate-active-enzymes-database-cazy-in-2013-37p3bw39e7.pdf

The carbohydrate-active enzymes database (CAZy) in 2013

Glycobiology: Toward Understanding the Function of Sugars.

Neutralizing antibodies (Nab) are a principal component of an effective human immune response to many pathogens, yet their role in HIV-1 infection is unclear. To gain a better understanding of this role, we examined plasma from patients with acute HIV infection. Here we report the detection of autologous Nab as early as 52 days after detection of HIV-specific antibodies. The viral inhibitory activity of Nab resulted in complete replacement of neutralization-sensitive virus by successive populations of resistant virus. Escape virus contained mutations in the env gene that were unexpectedly sparse, did not map generally to known neutralization epitopes, and involved primarily changes in N-linked glycosylation. This pattern of escape, and the exceptional density of HIV-1 envelope glycosylation generally, led us to postulate an evolving 'glycan shield' mechanism of neutralization escape whereby selected changes in glycan packing prevent Nab binding but not receptor binding. Direct support for this model was obtained by mutational substitution showing that Nab-selected alterations in glycosylation conferred escape from both autologous antibody and epitope-specific monoclonal antibodies. The evolving glycan shield thus represents a new mechanism contributing to HIV-1 persistence in the face of an evolving antibody repertoire.

Antibody neutralization and escape by HIV-1

Roles for glycosylation in the anti-inflammatory molecule CD59

Glycosidase inhibitors in British plants as causes of livestock disorders.

The crystal structure of the title diacetone psicose, C12H20O6, establishes the stereochemistry of the anomeric spiro­acetal 1,2:3,4-di-O-isopropyl­idene-β-d-psicofuran­ose. The structure consists of columns of mol­ecules linked by hydrogen bonds into chains [O⋯O 2.962 (2) A] lying parallel to the a axis.

/pdf/1-2-3-4-di-o-isopropyl-idene-b-d-psicofuran-ose-1jphc5ratn.pdf

1,2:3,4‐Di‐O‐isopropyl­idene‐β‐d‐psicofuran­ose

A practical synthesis of the very rare sugar d-idose and the stable building blocks for d-idose, d-iduronic, and d-idonic acids from ido-heptonic acid requires only isopropylidene protection, Shing silica gel-supported periodate cleavage of the C6-C7 bond of the heptonic acid, and selective reduction of C1 and/or C6. d-Idose is the most unstable of all the aldohexoses and a stable precursor which be stored and then converted under very mild conditions into d-idose is easily prepared.

https://www.mdpi.com/1420-3049/24/20/3758/pdf

d-Idose, d-Iduronic Acid, and d-Idonic Acid from d-Glucose via Seven-Carbon Sugars.

Stable amides and oligopeptides derived from methyl trans,trans -3-azido-4-hydroxymethyl- l -azetidine carboxylate, prepared in 19% yield from diacetone allose, is the first example of a β-amino-azetidine carboxylic acid incorporated into peptidomimetics and provides a scaffold for investigating secondary structure induced by a novel β-amino acid. A number of azetidine iminosugars containing a NHAc substituent were prepared but none of them were β- N -acetylhexosaminidase inhibitors.

/pdf/3-azidoazetidines-as-the-first-scaffolds-for-b-amino-4d19edwb93.pdf

3-Azidoazetidines as the first scaffolds for β-amino azetidine carboxylic acid peptidomimetics: azetidine iminosugars containing an acetamido group do not inhibit β-N-acetylhexosaminidases

Mark R. Wormald

Papers

Roles for glycosylation in the anti-inflammatory molecule CD59

Glycosidase inhibitors in British plants as causes of livestock disorders.

1,2:3,4‐Di‐O‐isopropylidene‐β‐d‐psicofuranose

d-Idose, d-Iduronic Acid, and d-Idonic Acid from d-Glucose via Seven-Carbon Sugars.

3-Azidoazetidines as the first scaffolds for β-amino azetidine carboxylic acid peptidomimetics: azetidine iminosugars containing an acetamido group do not inhibit β-N-acetylhexosaminidases

Mark R. Wormald

Papers

Roles for glycosylation in the anti-inflammatory molecule CD59

Glycosidase inhibitors in British plants as causes of livestock disorders.

1,2:3,4‐Di‐O‐isopropyl­idene‐β‐d‐psicofuran­ose

d-Idose, d-Iduronic Acid, and d-Idonic Acid from d-Glucose via Seven-Carbon Sugars.

3-Azidoazetidines as the first scaffolds for β-amino azetidine carboxylic acid peptidomimetics: azetidine iminosugars containing an acetamido group do not inhibit β-N-acetylhexosaminidases

1,2:3,4‐Di‐O‐isopropylidene‐β‐d‐psicofuranose