Purifying a Mutated Carbon Monoxide Binding Protein, CooA C75S

Proteins in certain organisms have the ability to bind the molecule carbon monoxide. One of these proteins is the CooA protein, which exists in similar forms in two organisms: C. hydrogenoformans and R. rubrum. The R. rubrum CooA protein is very selective for carbon monoxide only, possibly due to the presence of a cysteine amino acid at position 75 in the structure of the protein. The CooA from C. hydrogenoformans does not have a cysteine amino acid in this position and binds more promiscuously, binding nitric oxide as well as carbon monoxide, for example. In order to test the hypothesis that the cysteine amino acid at position 75 causes the high selectivity of the R. rubrum CooA towards carbon monoxide, we expressed and purified a mutated CooA protein from R. rubrum in which the cysteine at position 75 was mutated to a serine amino acid. If the purification is successful, the mutant R. rubrum CooA can then be tested to see if it now binds nitric oxide as well as carbon monoxide, like the C. hydrogenoformans CooA protein

Ligand Binding Studies of Metalloporphyrins

Porphyrin molecules are found in numerous proteins important in biological processes. The porphyrin used in this project, tetraphenylprophryin (TPP), is a model compound used to study the iron-containing porphyrin found in hemoglobin responsible for transporting oxygen in the blood. In this work, TPP was synthesized and several metals including Zinc, Iron, and Manganese were reacted with TPP to form metalloporphyrins. UV-Visible and NMR spectroscopy was used to confirm the correct identity of products. The addition of amine ligands to these metalloporphyrins was then performed to study how metal identity affects ligand binding. To date, trials using pyrrolidine and piperidine have been performed successfully with more amines to be attempted later

MDS-352 Myelodysplastic syndromes with concomitant SF3B1 mutation and deletion of the long arm of chromosome 5

Concomitant SF3B1 and del(5q) are classified as myelodysplastic syndromes (MDS) del(5q). Lenalidomide (Len) is the treatment of choice for isolated del(5q) MDS and luspatercept (Luspa) for MDS-SF3B1. There is scarce data about the response of this entity to either Len or Luspa. This multicenter, international, retrospective analysis included patients diagnosed with concomitant del(5q)/SF3B1, less than 5% myeloblasts, and no complex karyotype. We included 77 low-risk MDS (LR-MDS) patients with isolated del(5q)/SF3B1. The mOS for all was 66 months (95% CI: 53–79). The mOS was 109 months for TP53 WT compared to 64 months for TP53 MT (P=0.22). First-line was Len for 46 patients (61%), ESA for 18 patients (23%), Luspa for 4 patients (5%), hypomethylating agents for 6 patients (8%), and other therapies for 2 patients (3%). Among 72 evaluable patients for response, the best HI rate to first-line therapy was 53% (37 patients). The HI rate to Len, ESA, HMA, and Luspa was 64%, 42%, 20%, and no response, respectively, as first line. Forty-seven patients received second-line therapy, 12 (26%) Len, 4 (9%) Luspa, 22 (47%) HMA, 1 ESA, and 8 (17%) others. Among 39 evaluable patients, the best HI rate to second-line therapy was 43% (17 patients). The HI rate was 46% (5/11 patients), 50% (2/4 patients), and 47% (8/17 patients) for Len, Luspa, and HMA as second-line therapy, respectively. Thirty-eight patients received ESA at any time, among 33 patients evaluable for response, HI rate was 27% (9 patients). Sixty patients received Len, at any time, among 57 patients evaluable for response, HI rate was 59%. There was no difference in response among TP53 WT 61% vs 50% for TP53 MT (P=.4). A total of 16 patients received Luspa at any time where HI rate was 18% (3 patients). Finally, 37 patients received HMA at any time, and among 32 responses evaluable HMA-treated patients, the HI was 37% (12 patients). The mOS of 66 months for concomitant del(5q)/SF3B1 is still inferior to the isolated entities. Our data suggest that Len should be first-line therapy for those patients followed by Luspa and HMA