When the menu comes up, select Console.In the Jmol applet showing the 3D structure, click on the Jmol logo (or frank) in the bottom right corner.The values for these two angles can be determined for the residue of any protein entry in Proteopedia by doing the following: Even though the are the same in both peptides, the remainder of the peptide chains do not overlay. The yellow reference planes of the two peptides occupy the same space, and therefore since the phi values are different the orange planes are in different locations. The peptides diverge at the with the carbonyl groups of Leu47 being in different locations. The peptides were overlaid so that the Tyr and Ile of the two peptides overlay each other. With a second peptide (red chain) whose sequence is identical to the original peptide (green chain) and whose phi & psi values are the same except for the Ile which has phi = -49 o rather than -149 o. The phi for Leu47 is set by rotating the (plane of the Leu46-Leu47 peptide bond). Since the does not leave the plane of the peptide bond, the rotation of the α-carbon changes the angle of the yellow plane relative to the plane of the peptide bond (orange and purple), and thus sets the the psi for Leu47. The (larger diameter sticks) can be rotated to set psi for Leu47. With this being the case the psi for Leu47 can not be set by rotating this peptide bond plane because in doing so the Ile phi value would change. Notice that the orange plane involved in setting phi = -149 o is in the same peptide bond plane as the purple plane that sets psi for Leu at -34 o.
An amino acid needs to be bonded to in order to have values set for both psi and phi, for that reason the two terminal amino acids do not have values set for these angles. The orange plane is part of the between Ile and Leu (blue plane), and the angle between the blue and yellow planes is phi. The purple plane is part of the (side chains removed for clearer viewing) between Tyr and Ile (red plane), and the angle between the red and yellow planes is psi. The yellow plane serves as the references in measuring the two angles. Notice the three colored triangular planes. The initial scene shows phi and psi values for Ile. Of two other peptide bonds, and then using the technique described above identify the atoms contained in and the numerical values of the φ and ψ angles of the α-carbon connected to these two planes. that you correctly determined direction of rotation and the values of φ and ψ. After rotating the structure so that the four atoms can be clearly seen, measure and display the numerical value of ψ using the technique described above. (If the structure rotates in the course of clicking on the atoms or if you encounter some other problem, re-click on the green link 'four atoms' and restart clicking on the atoms.) The which constitute a ψ are an amide nitrogen, a carbonyl carbon, an α-carbon and a second nitrogen. After toggling off spin and rotating the structure so that you can clearly see that you are not clicking on a transparent atom, determine and display the numerical value of φ by double clicking on a carbonyl carbon of the angle, single clicking on the next two atoms and then double clicking on the second carbonly. The making up φ are a carbonyl carbon, the connecting α-carbon, an amide nitrogen and the next carbonyl carbon (all marked with green halos). 1 Determining values for phi (φ) and psi (ψ)ĭetermining values for phi (φ) and psi (ψ).The character table below is showing a pixel precise graphical representation for each character, alongside with a text description.
Only the extended character set differs from the original code page, both the control characters and the standard character set being plain ASCII. It is not very popular, Code page 737 being the most widely used one. The characters in the 128-255 range are referred to as extended ASCII.Ĭode page 869 is an alternative code page used to write Greek language. It later was expanded to support 256 characters (8-bit code) in order to provide language specific characters, various symbols, as well as box-drawing characters: elements used for presentation purposes, allowing to draw different kind of frames and boxes. The first 32 characters are control characters (also called non-printable characters), which are used to control data streams as well as devices such as printers. The original character set, which is now referred as the standard character set was initially composed of 128 characters (7-bit code). American Standard Code for Information Interchange ( ASCII) is a widely used character encoding system introduced in 1963.
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