The human genome holds an extraordinary trove of information about human development, physiology, medicine and evolution. Here we report the results of an international collaboration to produce and make freely available a draft sequence of the human genome. We also present an initial analysis of the data, describing some of the insights that can be gleaned from the sequence.

/pdf/initial-sequencing-and-analysis-of-the-human-genome-5dapk1rsx1.pdf

Initial sequencing and analysis of the human genome.

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

CHAPTER 24 – Evolution of Protein Molecules

Semiconductor nanocrystals were prepared for use as fluorescent probes in biological staining and diagnostics. Compared with conventional fluorophores, the nanocrystals have a narrow, tunable, symmetric emission spectrum and are photochemically stable. The advantages of the broad, continuous excitation spectrum were demonstrated in a dual-emission, single-excitation labeling experiment on mouse fibroblasts. These nanocrystal probes are thus complementary and in some cases may be superior to existing fluorophores.

https://science.sciencemag.org/content/sci/281/5385/2013.full.pdf

Semiconductor Nanocrystals as Fluorescent Biological Labels

Highly luminescent semiconductor quantum dots (zinc sulfide-capped cadmium selenide) have been covalently coupled to biomolecules for use in ultrasensitive biological detection. In comparison with organic dyes such as rhodamine, this class of luminescent labels is 20 times as bright, 100 times as stable against photobleaching, and one-third as wide in spectral linewidth. These nanometer-sized conjugates are water-soluble and biocompatible. Quantum dots that were labeled with the protein transferrin underwent receptor-mediated endocytosis in cultured HeLa cells, and those dots that were labeled with immunomolecules recognized specific antibodies or antigens.

http://science.sciencemag.org/content/sci/281/5385/2016.full.pdf

Quantum Dot Bioconjugates for Ultrasensitive Nonisotopic Detection

Phycobilisomes of the cyanobacterium Synechococcus 6301 contain the phycobiliproteins phycocyanin, allophycocyanin, and allophycocyanin B, and four major non pigmented polypeptides of 75, 33, 30, and 27 kdaltons. The molar ratio of phycocyanin to allophycocyanin in wild type phycobilisomes can be varied over about a two-fold range by alterations in culture conditions with parallel changes in the amounts of the 33 and 30 kdalton polypeptides whereas the levels of the 27 and 75 kdalton polypeptides do not vary. Two nitrosoguanidine-induced mutants, AN112 and AN135, produce abnormally small phycobilisomes, containing only 35 and 50% of the wild type level of phycocyanin. AN135 phycobilisomes contain less 33 kdalton polypeptide than wild type and the 30 kdalton polypeptide is only detected in phycobilisomes from cultures grown under conditions favoring high levels of phycocyanin. AN112 lacks both the 30 and 33 kdalton polypeptides and produces phycobilisomes of constant size and composition, independent of growth conditions. Both mutant phycobilisomes have wild type levels of 27 and 75 kdalton polypeptides relative to allophycocyanin and have normal energy transfer properties. These results indicate that modulation of phycobilisome size involves concurrent regulation of the levels of phycocyanin and of both the 30 and 33 kdalton polypeptides with no change in the composition of the allophycocyanin-containing core.

Dynamic aspects of phycobilisome structure: Modulation of phycocyanin content of Synechococcus phycobilisomes

Allophycocyanin B was purified to homogeneity from the eukaryotic red alga Porphyridium cruentum. This biliprotein is distinct from the allophycocyanin of P. cruentum with respect to subunit molecular weights, and spectroscopic and immunological properties. The purified allophycocyanin B has a long wavelength absorption maximum at 669 nm at room temperature and at 675 nm at −196 C while the fluorescence emission maximum is at 673 nm at room temperature and 679 nm at −196 C. The emission spectrum of allophycocyanin shifted only 1 nm, from 659 to 660 nm, on cooling to −196 C, and was the same with allophycocyanin crystals as it was with pure solutions of the pigment. Phycobilisomes from P. cruentum have a major fluorescence emission band at 680 nm at −196 C which emanates from the small amount of allophycocyanin B present in the phycobilisomes. Light energy absorbed by the bulk of the biliprotein pigments is transferred to allophycocyanin B with high efficiency.

/pdf/isolation-and-function-of-allophycocyanin-b-of-porphyridium-wlkpuw2hnz.pdf

Alexander N. Glazer

Papers

Dynamic aspects of phycobilisome structure: Modulation of phycocyanin content of Synechococcus phycobilisomes

Isolation and Function of Allophycocyanin B of Porphyridium cruentum

Molecular architecture of a light-harvesting antenna. Isolation and characterization of phycobilisome subassembly particles.

Structure-Function Relationships in Lysozyme by Circular Dichroism1

Phycoerythrins as chemotaxonomic markers in red algae: A survey