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

Superoxide dismutase: Improved assays and an assay applicable to acrylamide gels☆

The Role of Superoxide Anion in the Autoxidation of Epinephrine and a Simple Assay for Superoxide Dismutase

Hydroperoxide metabolism in mammalian organs.

The occurrence of superoxide anion in the reaction of reduced phenazine methosulfate and molecular oxygen

Oxidative Protein Folding Is Driven by the Electron Transport System

Flavin-oxygen derivatives involved in hydroxylation by p-hydroxybenzoate hydroxylase.

Nitric oxide (NO) functions as a signaling agent by activation of the soluble isoform of guanylate cyclase (sGC), a heterodimeric hemoprotein. NO binds to the heme of sGC and triggers formation of cGMP from GTP. Here we report direct kinetic measurements of the multistep binding of NO to sGC and correlate these presteady state events with activation of enzyme catalysis. NO binds to sGC to form a six-coordinate, nonactivated, intermediate (k(on) > 1.4 x 10(8) M(-1).s(-1) at 4 degrees C). Subsequent release of the axial histidine heme ligand is shown to be the molecular step responsible for activation of the enzyme. The rate at which this step proceeds also depends on NO concentration (k = 2.4 x 10(5) M(-1).s(-1) at 4 degrees C), thus identifying a novel mode of regulation by NO. NO binding to the isolated heme domain of sGC was also rapid (k = 7.1 +/- 2 x 10(8) M(-1).s(-1) at 4 degrees C); however, no intermediate was observed. The data show that sGC acts as an extremely fast, specific, and highly efficient trap for NO and that cleavage of the iron-histidine bond provides the driving force for activation of sGC. In addition, the kinetic data indicate that transport or stabilization of NO is not necessary for effective signal transmission.

https://www.pnas.org/content/pnas/96/26/14753.full.pdf

David P. Ballou

Papers

Oxidative Protein Folding Is Driven by the Electron Transport System

Flavin-oxygen derivatives involved in hydroxylation by p-hydroxybenzoate hydroxylase.

A molecular basis for nitric oxide sensing by soluble guanylate cyclase

The Mechanism of Action of Xanthine Oxidase

Separate roles for FMN and FAD in catalysis by liver microsomal NADPH-cytochrome P-450 reductase.