Question

Discus genetically modified proteins and provide a reference.

Answer 1

Genetically modified proteins are produced by site-specific mutagenesis and chimeragenesis for the functional improvement of proteins in areas where traditional protein engineering methods have been extensively used and practically exhausted. The novel path for the creation of the novel proteins has been created on the farther development of the new structure and sequence optimization algorithms for generating and designing the accurate structure models in the result of x-ray crystallography studies of a lot of proteins and their mutant forms. Artificial genetic modifications aim to expand nature's repertoire of biomolecules. One of the most exciting potential results of mutagenesis or chimeragenesis finding could be the design of effective diagnostics, biotherapeutics and biocatalysts.

Mutations such as amino acid substitution, sequence deletion/insertion or DNA shuffling are selected depending on their impact on the chemical nature of catalytic residues, active site conformation, dynamical flexibility, local packing density, relative solvent accessibility, multimeric complexity, and the protein's ability to fold rapidly and stable. There is sufficient data to study how proteins of living organism adapt to changes in the environment and how this is connected with cell metabolism and its regulation. Several levels of regulation such as transcription, translation, protein stability, enzyme regulation ensure that the response is optimal.

Reference: Metabolic adaptation and protein complexes in prokaryotes.

Krüger B, Liang C, Prell F, Fieselmann A, Moya A, Schuster S, Völker U, Dandekar T

Metabolites. 2012 Nov 16; 2(4):940-58.

There are many examples of genetic modification of proteins in nature by recombination of sequences or domains between homologous proteins for obtaining chimeras with improved properties. The mammalian galectin-3 and galectin from the sponge, Geodia cydonium, and other members of this subfamily have chimera-type characteristic and sequence polymorphism within their carbohydrate recognition domains.

Reference: The Geodia cydonium galectin exhibits prototype and chimera-type characteristics and a unique sequence polymorphism within its carbohydrate recognition domain.

Stalz H, Roth U, Schleuder D, Macht M, Haebel S, Strupat K, Peter-Katalinic J, Hanisch FG

Glycobiology. 2006 May; 16(5):402-14.