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Protein Nanotubes with an Enzyme Interior Surface
Author(s) -
Komatsu Teruyuki,
Terada Hiromi,
Kobayashi Nao
Publication year - 2011
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201001937
Subject(s) - materials science , monolayer , nanotube , hydrolysis , chemical engineering , substrate (aquarium) , aqueous solution , layer (electronics) , human serum albumin , chemistry , chromatography , nanotechnology , carbon nanotube , organic chemistry , oceanography , geology , engineering
This report describes the synthesis and enzyme activities of multilayered protein nanotubes with an α‐glucosidase (αGluD) interior surface. The nanotubes were prepared by using an alternating layer‐by‐layer (LbL) assembly of human serum albumin (HSA) and oppositely charged poly‐ L ‐arginine (PLA) into a track‐etched polycarbonate (PC) membrane (pore size=400 nm) followed by addition of αGluD as the last layer of the wall. Subsequent dissolution of the PC template yielded (PLA/HSA) 2 PLA/αGluD nanotubes. SEM measurements revealed the formation of uniform hollow cylinders with (413±17) nm outer diameter and (52±3) nm wall thickness. In aqueous media, the nanotubes captured a fluorogenic glucopyranoside, 4‐methyl‐umbelliferyl‐α‐ D ‐glucopyranoside (MUGlc), into their one‐dimensional pore space and hydrolyzed the substrate efficiently to form α‐ D ‐glucose. We determined the enzyme parameters (Michaelis constant, K M , and catalytic constant, k cat , values) of the protein nanotubes. The several‐micrometers‐long cylinders were of sufficient length to be spun down by centrifugation at 4000 g , so the product could therefore be easily separated. Similar biocatalysts were prepared by complexation of biotinylated‐αGluD into HSA‐based nanotubes bearing a single avidin layer as an internal surface. The obtained hybrid nanotubes also exhibited the same enzyme activity for the MUGlc hydrolysis.