<s>
SOSUI	B-Application
is	O
a	O
free	O
online	O
tool	O
that	O
predicts	O
a	O
part	O
of	O
the	O
secondary	O
structure	O
of	O
proteins	O
from	O
a	O
given	O
amino	O
acid	O
sequence	O
(	O
AAS	O
)	O
.	O
</s>
<s>
SOSUI	B-Application
's	O
algorithm	O
was	O
developed	O
in	O
1996	O
at	O
Tokyo	O
University	O
.	O
</s>
<s>
First	O
of	O
all	O
,	O
SOSUI	B-Application
looks	O
for	O
α	O
helices	O
that	O
are	O
relatively	O
easy	O
to	O
predict	O
,	O
taking	O
into	O
account	O
the	O
known	O
helical	O
potentials	O
of	O
the	O
given	O
amino	O
acid	O
sequence(AAS )	O
.	O
</s>
<s>
SOSUI	B-Application
uses	O
4	O
characteristics	O
of	O
the	O
AAS	O
in	O
its	O
prediction	O
:	O
</s>
<s>
To	O
meet	O
SOSUI	B-Application
's	O
criteria	O
for	O
amphiphilicity	O
,	O
the	O
polar	O
,	O
hydrophilic	O
residue	O
may	O
not	O
be	O
linked	O
directly	O
to	O
the	O
beta-carbon	O
;	O
there	O
must	O
be	O
at	O
least	O
one	O
apolar	O
carbon	O
interposed	O
(	O
therefore	O
only	O
lysine	O
,	O
arginine	O
,	O
histidine	O
,	O
glutamic	O
acid	O
,	O
glutamine	O
,	O
tryptophan	O
and	O
tyrosine	O
are	O
relevant	O
)	O
.	O
</s>
<s>
SOSUI	B-Application
then	O
looks	O
for	O
accumulations	O
of	O
amphiphilic	O
AAs	O
at	O
the	O
ends	O
of	O
α	O
helices	O
,	O
which	O
seems	O
to	O
be	O
typical	O
for	O
transmembrane	O
α	O
helices	O
(	O
it	O
makes	O
the	O
transmembrane	O
position	O
the	O
energetically	O
best	O
one	O
for	O
these	O
α	O
helices	O
by	O
placing	O
amphiphilic	O
AAs	O
at	O
the	O
lipid-water	O
boundary	O
and	O
is	O
thus	O
co-responsible	O
for	O
the	O
protein	O
's	O
correct	O
localization	O
)	O
.	O
</s>
<s>
According	O
to	O
a	O
study	O
published	O
by	O
SOSUI	B-Application
's	O
developers	O
it	O
successfully	O
differentiated	O
99%	O
of	O
a	O
chosen	O
group	O
of	O
proteins	O
with	O
known	O
structure	O
.	O
</s>
<s>
However	O
,	O
another	O
study	O
that	O
had	O
several	O
prediction	O
tools	O
perform	O
on	O
the	O
AAS	O
's	O
of	O
122	O
known	O
proteins	O
claimed	O
that	O
SOSUI	B-Application
was	O
correct	O
about	O
the	O
number	O
of	O
α	O
helices	O
in	O
only	O
about	O
60%	O
of	O
the	O
cases	O
.	O
</s>
<s>
porins	O
)	O
or	O
which	O
are	O
fixed	O
with	O
a	O
covalent	O
bond	O
cannot	O
be	O
found	O
by	O
SOSUI	B-Application
.	O
</s>
