Gene expression and development : the third of five volumes constituting the proceedings of the 4th International Congress on Isozymes, held in Austin, Texas, June 14-19, 1982 / editors, Mario C. Rattazzi, John G. Scandalios, Gregory S. Whitt.
- International Congress on Isozymes
- Date:
- [cl983]
Licence: Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)
Credit: Gene expression and development : the third of five volumes constituting the proceedings of the 4th International Congress on Isozymes, held in Austin, Texas, June 14-19, 1982 / editors, Mario C. Rattazzi, John G. Scandalios, Gregory S. Whitt. Source: Wellcome Collection.
66/256 page 46
![46 / Bewley t/1 0) о. о U 0) + © 0^ 3 ^ о о Ь ó ®оо' о о '^О '^о 1бО 'Ю GPDH-1 Ö п б О ,80 ~ Chromatography Fig. 6. Peptide map generated by Staphylococcus aureus V8 protease of oxidized GPDH''- 1. Peptides from 1.7 mg of protein were separated by a two-dimensional peptide map, as described in Figure 4. The carboxyl-terminal peptide is denoted by hatching. From Niesel et al [1982], with permission. properties reported in Table I. First, as the result of the removal of a tri peptide sequence from GPDH'^-S, a shift in the conformation on the polypeptide chain would be likely. Conformational changes in the polypeptide structure can be proposed 1) to alter the net charge on the molecule, thereby affecting the native isoelectric point and electrophoretic migration under nondenaturing conditions, 2) to produce a new conformation that is highly labile to thermal denaturation, and 3) to cause slight variation in active-site positioning, ac¬ counting for the shift in kinetic and ligand-binding properties. If the expression of each GPDH isozyme is accomplished by a shortening of the carboxyl-terminal region, then certain predictions can be advanced as to the origin of each form. First, both isozymes must be encoded by the same structural gene. From accumulated data, it would be difficult to believe that they arise from separate genes, differing in an abbreviation of the car¬ boxyl-terminal region. Second, if each isozyme arises by a post-translational mechanism, the primary gene product would have to code for the GPDH'^- 1 polypeptide with a subsequent proteolytic cleavage at the COOH-terminus to produce GPDH-3 subunits. It is also possible that the expression of each](https://iiif.wellcomecollection.org/image/b18019742_0067.JP2/full/800%2C/0/default.jpg)
