02652nas a2200205 4500008004100000022001400041245013700055210006900192260009100261300001300352490000700365520181000372100002102182700001902203700002202222700002402244700003302268700002202301856012302323 2015 eng d a1932-620300aGedunin and azadiradione: human pancreatic alpha-amylase inhibiting limonoids from neem (azadirachta indica) as anti-diabetic agents0 aGedunin and azadiradione human pancreatic alphaamylase inhibitin a1160 BATTERY STREET, STE 100, SAN FRANCISCO, CA 94111 USAbPUBLIC LIBRARY SCIENCEcOCT ae01401130 v103 a

Human pancreatic alpha-amylase (HPA) inhibitors offer an effective strategy to lower postprandial hyperglycemia via control of starch breakdown. Limonoids from Azadirachta indica known for their therapeutic potential were screened for pancreatic alpha-amylase inhibition, a known anti-diabetic target. Studies were carried out to reveal their mode of action so as to justify their hypoglycemic potential. Of the nine limonoids isolated/semi-synthesized from A. indica and screened for alpha-amylase inhibition, azadiradione and exhibited potential inhibition with an IC50 value of 74.17 and 68.38 mu M, respectively against HPA under in vitro conditions. Further screening on AR42J alpha-amylase secretory cell line for cytotoxicity and bioactivity revealed that azadiradione and gedunin exhibited cytotoxicity with IC50 of 11.1 and 13.4 mu M. Maximal secreted alpha-amylase inhibition of 41.8% and 53.4% was seen at 3.5 and 3.3 mu M, respectively. Michaelis-Menten kinetics suggested a mixed mode of inhibition with maltopentaose (K-i 42.2, 18.6 mu M) and starch (K-i' 75.8, 37.4 mu M) as substrate with a stiochiometry of 1: 1 for both azadiradione and gedunin, respectively. The molecular docking simulation indicated plausible p-alkyl and alkyl-alkyl interactions between the aromatic amino acids and inhibitors. Fluorescence and CD confirmed the involvement of tryptophan and tyrosine in ligand binding to HPA. Thermodynamic parameters suggested that binding is enthalpically and entropically driven with Delta G degrees of -21.25 kJ mol(-1) and -21.16 kJ mol(-1) for azadiradione and gedunin, respectively. Thus, the limonoids azadiradione and gedunin could bind and inactivate HPA (anti-diabetic target) and may prove to be lead drug candidates to reduce/control post-prandial hyperglycemia.

1 aPonnusamy, Sudha1 aHaldar, Saikat1 aMulani, Fayaj, A.1 aZinjarde, Smita, S.1 aThulasiram, Hirekodathakallu1 aRaviKumar, Ameeta uhttps://library.ncl.res.in/content/gedunin-and-azadiradione-human-pancreatic-alpha-amylase-inhibiting-limonoids-neem-102426nas a2200253 4500008004100000022001400041245018900055210006900244260000800313300001100321490000800332520147300340653002201813653002901835653002301864653002601887653002001913100001801933700002001951700002001971700003301991700002002024856012802044 2022 eng d a1369-703X00aUnderstanding unfolding and refolding of the antibody fragment (Fab) III: mapping covalent and non-covalent interactions during in-vitro refolding of light chain, heavy chain, and Fab.0 aUnderstanding unfolding and refolding of the antibody fragment F cNOV a1086440 v1873 a

In-vitro refolding of the antibody fragments from inclusion bodies is a critical manufacturing bottleneck. We have previously reported that Fab refolding involves the formation of an intermediate. To further decode the refolding pathway, we have mapped the covalent and non-covalent interactions during in-vitro refolding of individual light chain (LC), heavy chain (HC), and intact Fab. Intrinsic fluorescence analysis was performed to map the non -covalent interactions, whereas time-dependent disulfide mapping was performed using LC-MS/MS analysis under non-reducing and reducing atmospheres. Refolding of purified LC, HC, and intact Fab (Biosimilar rHu Ranibi-zumab) was investigated in the study. Under the reducing condition, LC, HC, and intact Fab required around 96, 30, and 70 h, respectively, whereas, under non-reducing conditions, they required only 48, 10, and 48 h, respectively, to acquire the native conformation. The disulfide bond mapping revealed that the bond between LC_Cys23/Cys88 is more unstable. The peptides mapped with the inter-chain disulfide bond were identified at 48 h during the refolding and can be considered as the rate-limiting step in (Fab) refolding. We have also studied a new refolding strategy involving assembly of separately refolded LC and HC into Fab molecule. In this case the Fab refolding yield was low (18.0 +/- 1.36%), indicating inefficient assembly of refolded LC and HC chain into native Fab molecule.

10aAntibody fragment10aDisulfide bond formation10aIn-vitro refolding10aLight and heavy chain10arHu Ranibizumab1 aGani, Kayanat1 aChirmade, Tejas1 aUghade, Santosh1 aThulasiram, Hirekodathakallu1 aBhambure, Rahul uhttps://library.ncl.res.in/content/understanding-unfolding-and-refolding-antibody-fragment-fab-iii-mapping-covalent-and-non