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001-es BibID:	BIBFORM085802
Első szerző:	Kandra Lili (biokémikus)
Cím:	Action pattern of alpha-amylases on modified maltooligosaccharides / Lili Kandra, Gyöngyi Gyémánt, András Lipták
Dátum:	2002
ISSN:	0006-3088
Megjegyzések:	2-Chloro-4-nitrophenyl- (CNP) and 4,6-O-benzylidene-modi?ed 4-nitrophenyl-(Bnl-NP) β-maltooligosaccharides (DP 4-8) were synthesised from cyclodex-trins using a chemical procedure. For the preparation of CNP-maltooligosidesof longer chain length a new chemoenzymatic procedure was developed us-ing rabbit skeletal muscle glycogen phosphorylase b. These substrates wereused for further studies of the action pattern of porcine pancreatic α-amylase (PPA), human salivary α-amylase (HSA) and Bacillus licheniformisα-amylase (BLA). The hydrolysis products and the remaining substrates wereseparated and quanti?ed by HPLC. Our results suggest at least six subsitesin the binding region of HSA; four glycone (?4, ?3, ?2, ?1) and two aglyconbinding sites (+1, +2). The binding modes of the benzylidene derivatives indi-cated a favourable interaction between the Bnl group and subsite (?3) and anunfavourable one with subsite (?4). PPA exhibited a unique pattern of actionon CNP-maltooligosaccharides by cleaving maltotriose units from the nonre-ducing ends and leaving CNP-glycosides, or by cleaving CNP-G2units fromthe reducing ends to leave maltooligosaccharides. Modi?cation of the nonre-ducing end of NP glycosides to give a 4,6-O-benzylidene-D-glucopyranosylgroup indicated a favourable interaction between the Bnl group and the sub-sites (?3) and (?5) but an unfavourable one with subsite (?4), which re-sulted in a clear shift in the product pattern. The binding region is longer inBLA than in human amylases. Our results suggested the presence of at leasteight subsites; ?ve glycone binding sites and three aglycon ones. The bindingmodes of substrates will be discussed on the basis of the known features ofthe structures of α-amylases.
Tárgyszavak:	Természettudományok Kémiai tudományok konferenciacikk folyóiratcikk human salivary α-amylase porcine pancreatic α-amylase Bacilluslicheniformis α-amylase action patterns β-maltooligosaccharide glycosides chemoenzymatic syntheses
Megjelenés:	Biologia, Bratislava. - 57 : Suppl.11. (2002), p. 171-180. -
További szerzők:	Gyémánt Gyöngyi (1960-) (vegyész) Lipták András (1935-2012) (vegyész)
Pályázati támogatás:	T032005 OTKA FKFP 0426/2000 Egyéb
Internet cím:	Szerző által megadott URL Intézményi repozitóriumban (DEA) tárolt változat
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