PMID- 28279767
OWN - NLM
STAT- MEDLINE
DCOM- 20170509
LR  - 20220410
IS  - 1879-0003 (Electronic)
IS  - 0141-8130 (Linking)
VI  - 99
DP  - 2017 Jun
TI  - Chemical modification with phthalic anhydride and chitosan: Viable options for 
      the stabilization of raw starch digesting amylase from Aspergillus carbonarius.
PG  - 641-647
LID - S0141-8130(16)32659-9 [pii]
LID - 10.1016/j.ijbiomac.2017.03.022 [doi]
AB  - The raw starch digesting type of amylase (RSDA) presents greater opportunities 
      for process efficiency at cheaper cost and shorter time compared to regular 
      amylases. Chemical modification is a simple and rapid method toward their 
      stabilization for a wider application. RSDA from Aspergillus carbonarius was 
      modified with either phthalic anhydride (PA) or chitosan. Activity retention was 
      87.3% for PA-modified and 80.9% for chitosan-modified RSDA. Optimum pH shifted 
      from 5 to 7 after PA-modification. Optimum temperature changed from 30 degrees C (native) 
      to 30-40 degrees C and 60 degrees C for PA-modified and chitosan-modified, respectively. 
      Activation energy (kJmol(-1)) for hydrolysis was 13.5, 12.7, and 10.2 while the 
      activation energy for thermal denaturation was 32.8, 80.3, 81.9 for free, 
      PA-modified and chitosan-modified, respectively. The specificity constants 
      (V(max)/K(m)) were 73.2 for PA-modified, 63.1 for chitosan-modified and 77.1 for 
      native RSDA. The half-life (h) of the RSDA at 80 degrees C was increased from 6.1 to 25.7 
      for the PA-modified and 138.6 for the chitosan derivative. Modification also led 
      to increase in D value, activation enthalpy and Gibbs free energy of enzyme 
      deactivation. Fluorescence spectra showed that center of spectral mass decreased 
      for the PA-modified RSDA but increased for chitosan modified RSDA.
CI  - Copyright (c) 2017 Elsevier B.V. All rights reserved.
FAU - Nwagu, Tochukwu Nwamaka
AU  - Nwagu TN
AD  - Department of Microbiology, Faculty of Biological Sciences, University of 
      Nigeria, Nsukka, Nigeria. Electronic address: tochukwu.nwagu@unn.edu.ng.
FAU - Okolo, Bartholomew
AU  - Okolo B
AD  - Department of Microbiology, Faculty of Biological Sciences, University of 
      Nigeria, Nsukka, Nigeria.
FAU - Aoyagi, Hideki
AU  - Aoyagi H
AD  - Life Sciences and Bioengineering, Graduate School of Life and Environmental 
      Sciences, University of Tsukuba, Japan.
FAU - Yoshida, Shigeki
AU  - Yoshida S
AD  - Life Sciences and Bioengineering, Graduate School of Life and Environmental 
      Sciences, University of Tsukuba, Japan.
LA  - eng
PT  - Journal Article
DEP - 20170306
PL  - Netherlands
TA  - Int J Biol Macromol
JT  - International journal of biological macromolecules
JID - 7909578
RN  - 0 (Phthalic Anhydrides)
RN  - 9005-25-8 (Starch)
RN  - 9012-76-4 (Chitosan)
RN  - EC 3.2.1.- (Amylases)
RN  - UVL263I5BJ (phthalic anhydride)
SB  - IM
MH  - Amylases/*chemistry/*metabolism
MH  - Aspergillus/*enzymology
MH  - Biocatalysis
MH  - Chitosan/*chemistry/*pharmacology
MH  - Digestion
MH  - Enzyme Stability/drug effects
MH  - Hydrogen-Ion Concentration
MH  - Hydrolysis
MH  - Kinetics
MH  - Phthalic Anhydrides/*chemistry
MH  - Solanum tuberosum/chemistry
MH  - Starch/*metabolism
MH  - Temperature
OTO - NOTNLM
OT  - Acylation
OT  - Amination
OT  - Chitosan
OT  - Phthalic anhydride
OT  - Raw starch digesting amylase
OT  - Stabilization
EDAT- 2017/03/11 06:00
MHDA- 2017/05/10 06:00
CRDT- 2017/03/11 06:00
PHST- 2016/11/29 00:00 [received]
PHST- 2017/03/03 00:00 [revised]
PHST- 2017/03/03 00:00 [accepted]
PHST- 2017/03/11 06:00 [pubmed]
PHST- 2017/05/10 06:00 [medline]
PHST- 2017/03/11 06:00 [entrez]
AID - S0141-8130(16)32659-9 [pii]
AID - 10.1016/j.ijbiomac.2017.03.022 [doi]
PST - ppublish
SO  - Int J Biol Macromol. 2017 Jun;99:641-647. doi: 10.1016/j.ijbiomac.2017.03.022. 
      Epub 2017 Mar 6.