Our CD analyses compare favorably with the X-ray data.

It would appear that there is enough information in the CD spectrum of a protein to predict all types of secondary structure. Thus there are five independent 'superstructures', consisting of a mixture of standard secondary structures, in the proteins studied. Furthermore, when the same method is applied to protein secondary structure rather than CD, it is found that only five basis secondary structure vectors are needed to reconstruct the original protein secondary structure vectors. Each basis CD spectrum corresponds to a known mixture of secondary structures so that the coefficients that reconstruct the protein CD spectrum can also be used to predict secondary structure. Circular dichroism has also been one tool of choice in the pharmaceutical industry as a non-destructive technique for quality control on drug and protein production, process optimization, and bio. Thus, one can expect to extract five independent pieces of information from the CD spectrum of a protein. CD spectra in the Far-UV region (185 250 nm) can be used to determine protein secondary structure. Five basis CD spectra are needed to reconstruct the 16 original protein CD spectra that extend into the vacuum ultraviolet region to 178 nm. Circular dichroism (measured in molar ellipticity) is the difference in absorption of left-handed and right-handed circularly polarized light and can be observed in optically active molecules with chiral centers. The method is based on mathematical calculation of orthogonal basis CD spectra from the CD spectra of proteins with known secondary structure. Eight types of secondary structures are considered: helix parallel and antiparallel beta strand types I, II, and III beta turn all other beta turns combined and 'other' structures. A method is presented for predicting the secondary structure of a protein from its circular dichroism (CD) spectrum.

Circular dichroism protein