Difference between revisions of "Single particle analysis"
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The overview of single particle analysis is shown. | The overview of single particle analysis is shown. | ||
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Protein particles are ice-embedded in random directions, thus allowing the three-dimensional electron microscopic imaging of protein particles from various directions of 2D images/projections. The images allow the structural analysis of proteins using single particle analyses. | Protein particles are ice-embedded in random directions, thus allowing the three-dimensional electron microscopic imaging of protein particles from various directions of 2D images/projections. The images allow the structural analysis of proteins using single particle analyses. | ||
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| + | == 3D single particle analysis == | ||
| + | 3D single particle analysis is the following method: by assuming that each particle has the same structure although the projection angle is different, we can reconstruct 3D structure of the particle from each projection. The protocol was the below. | ||
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| + | 1. Extraction of particle 2D images. | ||
| + | * 電子顕微鏡画像の前処理 | ||
| + | * 電子顕微鏡画像から粒子画像の抽出(Display2) | ||
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| + | 2. 参照画像の作成 | ||
| + | * 参照画像の準備([[mrcImageModelCreate]], [[pdb2mrc]] etc.) | ||
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| + | 3. 3次元再構成 | ||
| + | * 参照画像から２次元の参照投影像のセットを生成([[mrc3Dto2D]]) | ||
| + | * 最も類似度（相関値）の高い参照投影像の角度を粒子画像の投影角として決定([[mrcImageAutoRotationCorrelation]]) | ||
| + | * 三次元像を再構成する([[mrc3Dto2D]]) | ||
| + | * 三次元像の分解能・質の確認([[mrcImageFourierShellCorrelation]], [[mrcImageFOMCalc]], etc.) | ||
| + | * 繰り返し（精密化） | ||
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In single particle analyses, the images of protein particles are collected, and images similar in the directions of three-dimensional projection are superimposed and averaged. The averaging results in low-noise two-dimensional images. These images are used again as references for positioning the original images to obtain new averaged images. | In single particle analyses, the images of protein particles are collected, and images similar in the directions of three-dimensional projection are superimposed and averaged. The averaging results in low-noise two-dimensional images. These images are used again as references for positioning the original images to obtain new averaged images. | ||
After repeating these procedures, three-dimensional angles (Euler angles) are determined to construct a three-dimensional structure. In addition, a re-projected image is created from the initial three-dimensional structure. The image is subjected to averaging through the superposition of the original image as a reference to reconstruct a three-dimensional structure. These procedures are repeated until the structure is stabilized, in order to complete a structural model. In this training, the principles of single particle analyses and single particle analyses using Eos will be learned. | After repeating these procedures, three-dimensional angles (Euler angles) are determined to construct a three-dimensional structure. In addition, a re-projected image is created from the initial three-dimensional structure. The image is subjected to averaging through the superposition of the original image as a reference to reconstruct a three-dimensional structure. These procedures are repeated until the structure is stabilized, in order to complete a structural model. In this training, the principles of single particle analyses and single particle analyses using Eos will be learned. | ||
Revision as of 01:55, 19 June 2013
The overview of single particle analysis is shown.
Protein particles are ice-embedded in random directions, thus allowing the three-dimensional electron microscopic imaging of protein particles from various directions of 2D images/projections. The images allow the structural analysis of proteins using single particle analyses.
3D single particle analysis
3D single particle analysis is the following method: by assuming that each particle has the same structure although the projection angle is different, we can reconstruct 3D structure of the particle from each projection. The protocol was the below.
1. Extraction of particle 2D images.
- 電子顕微鏡画像の前処理
- 電子顕微鏡画像から粒子画像の抽出(Display2)
2. 参照画像の作成
- 参照画像の準備(mrcImageModelCreate, pdb2mrc etc.)
3. 3次元再構成
- 参照画像から２次元の参照投影像のセットを生成(mrc3Dto2D)
- 最も類似度（相関値）の高い参照投影像の角度を粒子画像の投影角として決定(mrcImageAutoRotationCorrelation)
- 三次元像を再構成する(mrc3Dto2D)
- 三次元像の分解能・質の確認(mrcImageFourierShellCorrelation, mrcImageFOMCalc, etc.)
- 繰り返し（精密化）
In single particle analyses, the images of protein particles are collected, and images similar in the directions of three-dimensional projection are superimposed and averaged. The averaging results in low-noise two-dimensional images. These images are used again as references for positioning the original images to obtain new averaged images.
After repeating these procedures, three-dimensional angles (Euler angles) are determined to construct a three-dimensional structure. In addition, a re-projected image is created from the initial three-dimensional structure. The image is subjected to averaging through the superposition of the original image as a reference to reconstruct a three-dimensional structure. These procedures are repeated until the structure is stabilized, in order to complete a structural model. In this training, the principles of single particle analyses and single particle analyses using Eos will be learned.
