RESUMO
A Si(111) winged crystal has been designed to minimize anticlastic bending and improve sagittal focusing efficiency. The crystal was thin with wide stiffening wings. The length-to-width ratio of the crystal was optimized by finite element analysis, and the optimal value was larger than the `golden value'. The analysis showed that the slope error owing to anticlastic bending is less than the Darwin width. The X-rays were focused two-dimensionally using the crystal and a tangentially bent mirror. The observed profiles of the focal spot agreed well with the results of a ray-tracing calculation in the energy range from 8 to 17.5â keV. X-ray diffraction measurements with a high signal-to-noise ratio using this focusing system were demonstrated for a small protein crystal.
Assuntos
Muramidase/química , Difração de Raios X/métodos , Animais , Cristalização/instrumentação , Desenho de Equipamento , SíncrotronsRESUMO
The region spanning residues 95-146 of the rotavirus nonstructural protein NSP4 from the asymptomatic human strain ST3 has been purified and crystallized and diffraction data have been collected to a resolution of 2.6 Å. Several attempts to solve the structure by the molecular-replacement method using the available tetrameric structures of this domain were unsuccessful despite a sequence identity of 73% to the already known structures. A more systematic approach with a dimer as the search model led to an unexpected pentameric structure using the program Phaser. The various steps involved in arriving at this molecular-replacement solution, which unravelled a case of subtle variation between different oligomeric states unknown at the time of solving the structure, are presented in this paper.
Assuntos
Glicoproteínas/química , Estrutura Quaternária de Proteína , Rotavirus/química , Toxinas Biológicas/química , Proteínas não Estruturais Virais/química , Sequência de Aminoácidos , Cristalografia por Raios X , Modelos Moleculares , Dados de Sequência Molecular , Alinhamento de SequênciaAssuntos
Adjuvantes Imunológicos/efeitos adversos , Alumínio/efeitos adversos , Toxoide Diftérico/efeitos adversos , Pancreatopatias/induzido quimicamente , Vacina contra Coqueluche/efeitos adversos , Toxoide Tetânico/efeitos adversos , Animais , Vacina contra Difteria, Tétano e Coqueluche , Combinação de Medicamentos/efeitos adversos , Fibrose/induzido quimicamente , Fibrose/patologia , Cobaias , Pancreatopatias/patologiaRESUMO
The following amendments have been introduced to the Minimum Requirements for Human Serum Albumin (HSA) and Plasma Protein Fraction (PPF): 1) The upper limit of sodium content was fixed at 3.7 mg/ml; 2) test for chloride content was introduced; 3) sodium and chloride contents were required to be stated on the label; 4) use of zone electrophoresis was introduced in addition to the free-boundary electrophoresis; and 5) albumin content in HSA was lowered from 97% to 96%. Moreover, current problems in quality control which may require further amendments were discussed, namely: 1) limulus amoebocyte lysate test to replace or supplement the pyrogen test in rabbits; 2) attempt of quantitative expression of visual turbidity; 3) establishment of reference A and B blood group substances; 4) gel permeation analysis and scanning at 370-800 nm; and 5) test for prekallikrein activator (PKA).
