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Epoxide hydrolase StEH1, from potato, is similar in overall structural fold and catalytic mechanism to haloalkane dehalogenase DhlA from Xanthobacter autotrophicus . StEH1 displays low (promiscuous) hydrolytic activity with (2-chloro)- and (2-bromo)ethanebenzene producing 2-phenylethanol. To investigate possibilities to amplify these very low dehalogenase activities, StEH1 was subjected to targeted randomized mutagenesis at five active-site amino acid residues and the resulting protein library was challenged for reactivity towards a bait chloride substrate. Enzymes catalyzing the first half-reaction of a hydrolytic cycle were isolated following monovalent phage display of the mutated proteins. Several StEH1 derived enzymes were identified with enhanced dehalogenase activities.

The human milk trisaccharide 3'- sialyllactose was reacted with an excess of N-methyl-O-benzylhydroxylamine (MBHA) and the product 3'- sialyllactose-MBHA was isolated in high (91%) yield by solid-phase extraction. The isomeric trisaccharide 6'-sialyllactose-MBHA was also prepared, in this case by enzymatic sialylation of lactose-MBHA. A 50/50 mixture of the two sialyllactose-MBHA derivatives was easily separated by reversed-phase HPLC. The free oligosaccharides were recovered from their respective MBHA derivatives by acid hydrolysis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Chemical overexposures and war-related stress during the 1990-1991 Gulf War (GW) are implicated in the persisting pathological symptoms that many GW veterans continue to endure. These symptoms culminate into a disease known as Gulf War Illness (GWI) and affect about a third of the GW veteran population. Currently, comprehensive effective GWI treatment options are unavailable. Here, an established GWI mouse model was utilized to explore the (1) long-term behavioral and neuroinflammatory effects of deployment-related GWI chemicals exposure and (2) ability of the immunotherapeutic lacto-N-fucopentaose III (LNFPIII) to improve deficits when given months after the end of exposure. Male C57BL6/J mice (8-9 weeks old) were administered pyridostigmine bromide (PB) and DEET for 14 days along with corticosterone (CORT; latter 7 days) to emulate wartime stress. On day 15, a single injection of the nerve agent surrogate diisopropylfluorophosphate (DFP) was given. LNFPIII treatment began 7 months post GWI chemicals exposure and continued until study completion. A battery of behavioral tests for assessment of cognition/memory, mood, and motor function in rodents was performed beginning 8 months after exposure termination and was then followed by immunohistochemcal evaluation of neuroinflammation and neurogenesis. Within tests of motor function, prior GWI chemical exposure led to hyperactivity, impaired sensorimotor function, and altered gait. LNFPIII attenuated these motor-related deficits and improved overall grip strength. GWI mice also exhibited more anxiety-like behavior that was reduced by LNFPIII; this was test-specific. Short-term, but not long-term memory, was impaired by prior GWI exposure; LNFPIII improved this measure. In the brains of GWI mice, but not in mice treated with LNFPIII, glial activation was increased. Overall, it appears that months after exposure to GWI chemicals, behavioral deficits and neuroinflammation are present. Many of these deficits were attenuated by LNFPIII when treatment began long after GWI chemical exposure termination, highlighting its therapeutic potential for veterans with GWI., (© 2022 The Authors.)

Sugars were derivatized with N,O-dimethylhydroxylamine (DMHA) using a simple procedure. The disaccharides lactose and chitobiose and the human milk tetrasaccharides lacto-N-tetraose (LNT) and lacto-N-neotetraose (LNnT) were used as examples. The β-glycosylamines were formed exclusively in good yields (80-84%). The derivatives were very well suited for RP-HPLC, giving rise to single peaks for each sugar, without the usual complications caused by mutarotation. The LNT- and LNnT-derivatives separated very well on an ordinary RP-HPLC column, despite their close structural similarity. Also, three human milk pentasaccharides (LNF I, II and III) were derivatized with DMHA. Again, good separation of these isomers was obtained. The DMHA derivatization was easily reversed. The free oligosaccharides were recovered quantitatively by mild acidic hydrolysis. To demonstrate usefulness on a preparative scale, an LNDI-rich human milk oligosaccharide fraction was derivatized, and three HPLC fractions (one major and two minor) were collected. Hydrolysis and desalting gave saccharides LNDI, LNnDII, and LNDII, the latter mixed with minor amounts of LNnDI., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)