Study On The Mechanism Of Garlic Fat-soluble Sulfides Mediated Regulation Of Dehydrogenase Activity Through H₂S

In recent years,H2 S emerged as the third gaseous molecule which had been recognized to be an important cell signaling role similar to the former molecules of NO and CO.H2 S was involved in physiological and pathophysiological processes related to inflammation.Based on the latest literatures,diallyl disulfide(DADS)and diallyl trisulfide(DATS)acted as potent donors of the hydrogen sulfide(H2S),when they were exposed to reducing mercapto compounds.Therefore,the mechanism of H2 S in the organic sulfide system is worth further exploring.At the same time,proteases can reflect the interaction process between H2 S and proteins because of its catalytic activity.In this paper,the storage capacity of total H2 S in various sulfides(including garlic organic sulfides)solutions will be evaluated.Combined with the active enzyme system,the garlic sulfides reexamined under the mechanism of H2 S in order to reveal the new biological significance of garlic sulfides in physiological activities.(1)Compared and evaluated the storage capacity of total H2 S pool in different sulfides solutions.First,a colorimetric method was established to detect H2 S in the solutions;Second,inorganic H2 S donors(Na2S/Na HS/K2Sx)solutions released H2 S quickly.DATS/DADS/allicin acted as potent donors of the hydrogen sulfide(H2S)and H2 S can only be detected in the presence of GSH/DTT/ASH,while diallyl sulfide(DAS)was not the reserve of H2 S.Finally,the total H2 S storage capacity of these three types of sulfides evaluated.The disclosure of the total H2 S storage capacity of allicin has not been reported.(2)Explored the mechanism of action of sulfide on enzyme protein.First,the activity of alcohol dehydrogenase(ADH)and glucose-6-phosphate dehydrogenase(G6PD)was monitored by fluorescence spectrometry,Na2S/Na HS/K2 Sx,DATS/DADS/allicin can inhibit the enzyme activity.Then,thiol oxidant(H2O2),thiol derivative(NEM)and thiol protectant(DTT)was used to infer that the effect of Na2 S,Na HS,K2 Sx,DATS,DADS,allicin,H2O2 and NEM on protein may all occur on thiols.The regulations of DATS,DADS and allicin were similar to that of Na2S/Na HS/K2 Sx.(3)Explored the specific site of the mechanism on proteins by sulfides.Explored changes in the secondary structure of proteins by circular dichroism(CD).CD spectra of protein showed significant changes of protein treaded by Na2S/DADS/DATS/allicin,which indicated that H2 S might modify the secondary structure of protein;Explored the mechanism of protein primary structure by MALDI-TOF-MS/MS.DATS/DADS/allicin had the similar mechanism of regulating proteins with Na2S/Na HS/K2 Sx,through the reactions with cysteine thiols in proteins by S-sulfuration,then protein-SSH was derivatized to regulate protein activity.It showed that the garlic lipid-soluble sulfides DATS/DADS/allicin were natural potential H2 S donors,and it had a controlled characteristic of H2 S release,which was safer and more reliable.DATS/DADS/allicin could replace Na2S/Na HS/K2 Sx as hopeful natural substituents for H2 S.In this paper,DATS/DADS/allicin had regulatory mechanism of thiol-derived protein thiols was disclosed,which should be the biological basis of the physiological activity of organic sulfides in garlic,and corrected the misconception that the biological activity of garlic sulfides originates from antioxidant properties.