Molecular Basis of the Evolution of Methylthioalkylmalate Synthase and the Diversity of Methionine-Derived Glucosinolates.

The globally cultivated Brassica species possess diverse aliphatic glucosinolates, which are important for plant defense and animal nutrition. The committed step in the side chain elongation of methionine-derived aliphatic glucosinolates is catalyzed by methylthioalkylmalate synthase, which likely evolved from the isopropylmalate synthases of leucine biosynthesis. However, the molecular basis for the evolution of methylthioalkylmalate synthase and its generation of natural product diversity in Brassica is poorly understood. Here, we show that Brassica genomes encode multiple methylthioalkylmalate synthases that have differences in expression profiles and 2-oxo substrate preferences, which account for the diversity of aliphatic glucosinolates across Brassica accessions. Analysis of the 2.1 Å resolution x-ray crystal structure of Brassica juncea methylthioalkylmalate synthase identified key active site residues responsible for controlling the specificity for different 2-oxo substrates and the determinants of side chain length in aliphatic glucosinolates. Overall, these results provide the evolutionary and biochemical foundation for the diversification of glucosinolate profiles across globally cultivated Brassica species, which could be used with ongoing breeding strategies toward the manipulation of beneficial glucosinolate compounds for animal health and plant protection.

Surgical Approaches to Orbital Fractures: A Practical and Systematic Review.

Orbital fractures constitute a significant percentage of all midface injuries. Here, we present a contemporary evidence-based review of the major surgical approaches for orbital wall fractures and analyze the literature to compare all major surgical procedures and their complication rates. Method: A systematic review was conducted to compare surgical approaches (subciliary, transcaruncular, transconjunctival, subtarsal, and endoscopic) and postoperative complications in patients who underwent surgical fixation of orbital wall fractures. A database search in PubMed (PubMed Central, MEDLINE and Bookshelf) was performed for all articles containing the terms "orbital," "wall," "fracture," and "surgery" with different combinations. Results: A total of 950 articles were obtained and 25 articles were included, representing an analysis of 1137 fractures. The most frequent surgical approach was the endoscopic (33.3%) followed by the external surgical approaches, specifically transconjunctival (32.8%), subciliary (13.5%), subtarsal (11.5%), and transcaruncular (8.9%). The transconjunctival approach had a statistically significantly higher rate of complications (36.19%), followed by the subciliary (21.4%), and endoscopic approach (20.2%, P < 0.0001). The subtarsal approach had a statistically significantly lower rate of complications (8.2%) followed by the transcaruncular approach (14.0%, P < 0.0001). Conclusion: The subtarsal and transcaruncular approaches were observed to have the lowest rates of complications, whereas the transconjunctival, subciliary, and endoscopic approaches were reported to have higher rates of complications.

Imbibition of soybean seeds in warm water results in the release of copious amounts of Bowman-Birk protease inhibitor, a putative anticarcinogenic agent.

Protease inhibitors play a protective role against pathogenic microorganisms and herbivorous insects. The two predominant protease inhibitors of soybean seeds are the Kunitz trypsin inhibitor (KTI) and Bowman-Birk protease inhibitor (BBI). In this study, we report that soybean seeds incubated in warm water release large amounts of proteins into the surrounding media. Two-dimensional gel electrophoresis analysis of the seed exudates resulted in the separation of 93 distinct protein spots out of which 90 spots were identified by LC-MS/MS. The basic 7S globulin and the BBI are the two predominant proteins found in the soybean seed exudates. In addition to 7S and 11S seed storage proteins, others known to protect the seeds against pathogens and pests including KTI, peroxidase, α-galactosidase, and endo-1.3-ß-glucanase were also identified in the seed exudates. Soybean seed exudate obtained by incubating the seeds in warm water was also able to inhibit the growth of human breast cancer cell line MCF-7. Since soybean seeds release large amounts of enzymatically active BBI when immersed in warm water, our procedure could be exploited as a simplified alternative method for the preparation of BBI concentrate which is being used as a cancer chemoprotective agent.