E
gjJiI踵'
耐热
ß-
甘露聚糖酶基闲的克隆与表达及酶学性质
赵梅
魏喜换
王春娟
董运海
李剑芳不
邬敏辰
2
(1.
11:
i~j
大学食品学院,江苏无锡
214122;
2
江南大学尤锡医学院,江苏无锡
214122)
摘要:基于生物信息学和基因纽学分析的结果,采用
RT-PCR
技术从宇佐美曲霉
(Aspergillus
usamii)
EOOl
中克隆出一种糖苦水解酶
(GH)
26
家族日-甘露聚糖酶
(AuMan26A)
成熟肤编
码基因
(A
uman26A)
,
成功实现,其在毕赤酵母
(Pic
hiap
ω
toris)
GS115
中的异源表达。重组自-甘
露聚糖酶
(reAuMan26A)
的发酵上清液对角豆肢的酶活性为
28
1.
9
U/
mL
,纯化后比酶活为
228
1.
7
U/mg
。其最适反应温度
T
o
μ
为
40
"C;在
80
"C处理
60
min
后残留酶活性为
60%;90
"C时
的半衰期阳列为
10
min
,处理
60
min
后残留酶活性仍为
3313
毛;其最适
pH
为
5.5
,在
pH
5.0-7.0
的范围内较稳定;
Fe
2
+
和
Fe
3+对其有明显的抑制作用,其它所测金属离子和
EDTA
对其没有明显
的影响;所测酶的最适底物为角豆肢,其次是魔芋粉和瓜尔豆肢,其对角豆肢的
Km
和
V""'"
值分
别为
15.25
m
g/
mL
和
7
84
1.
9
U/
mg
o
reAuMan26A
良好的热稳定性使其在食品、饲料和纺织等工
业具有广阔的应用前景。
关键词:自-甘露聚糖酶;耐热性;基因克隆和表达;酶学性质
中图分类号
:TS
20
1.
25
文献标志码
:A
文章编号
:1673--1689(2014)06
一
0590--07
Gene Cloning and Expression of a Thermostable ß-Mannanase
and
It
s Enzymatic Properties
ZHA 0 Mei
1
,
WEI
Xihuan
J
,
WANG
Chunjuan
J
, DONG Yunhai
1
,
LI
Ji
α
nfan
g*
J
,
WU
Minchen
2
(1.
School
of
Food
Science
and
Technology
,
Jiangnan
University
,
Wuxi
214122
, China;
2.
Wuxi
Medical
School
,
Jiangnan
University
,
Wuxi
214122
, China)
Abstract:
Based on the bioinformatics
and
genomics analysis ,a glycoside
hydrolase(GH)
family
26
gene ,A uman26A , which
encodes
白
-mannanase
mature peptide was cloned from Aspergillus usamii
EOOl
by RT
-PC
R.
Then , it was successfully expressed in
Pi
chia
p
ω
toris
GS115. The recombinant
enzyme (reAuMan26A) activity of the fermentation supernatant towards locust
bean
gum was 28
1.
9
U/
m
L.
The specific activity of the purified enzyme was 228
1.
7 U/mg. The optimal temperature of
reAuMan26A was
40
"C.
After incubating at
80
"c
and
90
"c
for
60
min , the residual activities were
60%
and
33%
,respectively. The half-life (t
Il
2
9O
) of reAuMan26A at
90
"c
was
10
min. The optimal
pH
of reAuMan26A was 5.5 , and it was stable over a range of
pH
5.0
-7.0.
Its activity was not
significantly affected by metal ions and EDTA ,
but
inhibited by Fe
2
+ and Fe
3
+.
It
s most favorable
收稿日期:
2013-11-11
基金项目:国家自然科学基金项目(3
1271811
)。
i
通信作者:李剑芳(1
965-)
,女,ìJ苏无锡人,
J
学
NJ
才,教挠,f
0U
研究生导师,主要从事食
S~!J:
物技术研究
O
E-mail:
lijf@163.colll
590
Journal
of
Food
Science
alld
Biotechnology
\'"0
1.3
3 No.6
2014