Identification and Expression of Oat Hemoglobin

Sammanfattning: Hemoglobin is mainly viewed as an oxygen and carbon dioxide carrier in the blood of animals and thus essential for life as we know it. During the course of evolution, plants have also developed versions of this protein, for similar and different purposes, such as regulation of nitric oxide levels. A lot of research has been put into characterization of hemoglobin from monocots, including rice, barley and maize. However, another monocot, oat, has been a hot topic during recent years within nutritional sciences due to its discovered health benefits, leading to intense research on this crop and several oat-based products on the market. Due to its complex genomic structure, the genome was just recently elucidated. Therefore, this thesis has been focusing on identifying and expressing oat hemoglobin for the first time and investigating its potential future use as a Hemoglobin-based oxygen carrier and/or nutritional additive. In essence, three non-symbiotic hemoglobin were found with high similarity to hemoglobin from rice and barley (~83% and ~92%, respectively). During condition optimization for the expression, high cell density (~3) was the most important parameter to achieve reduced hemoglobin, while precise concentrations of induction compounds were less important. Spectrophotometric assays revealed expression of active hemoglobin. For purification, both cation and anion exchange chromatography was tested without successful results. Therefore, optimization of the purification protocol is must moving forward for future characterization of the hemoglobin. Despite this, these hemoglobin are a new and interesting research area that could be a benefit for modern medicine and nutritional sciences.