Sequence of proteases - chymotrypsin A - trypsin - elastase

(Serpin)-The X-ray crystal structure of the archetypal serine protease chymotrypsin (pdb code 4CHA). The three catalytic residues (His 57, Asp 102 and Ser 195) are labeled.

In the catalytic triad of chymotrypsin, trypsin, and elastase, the three proteases function at three important molecular '[...]' points. The sites are at amino acid residues of: histidine 57, aspartic acid 102, and serine 195.

The comparison for chymotrypsin A (cow), and trypsin (cow), and elastase (pig) is as follows:

Site: aspartic acid 102

Section showing aspartic acid 102:

-

x

73 75 80

85

90

95

99A

C

QGSSSEKI

QKLKI

AKVFK

NSKYN

SLTI'

T

INVVEGNQ

QFISA

SKSIV

HPSYN

SNTL'

E

LNQNNGTE

QYVGV

QKIVV

HPYWN

TDDVA

- (D=Aspartic Acid 102)

x

99B 102,3,4,5

106-110

115

120

121 5,126

C

'NNDITL

LKLST

AASFS

QTVSA

VCLPSA

T

'NNDITL

IKLKS

AASLN

SRVAS

ISLPT'

E

AGYDIAL

LRLAQ

SVTLN

SYVQL

GVLPRA

-

Entire comparison of the sequences

-

x

1,2,3,4,5

6-10

15

20

C-Chymotrypsin

CGVPA

IQPVL

SGL(SR)

IVNGE

T-Trypsin

'`'`'

`'`'(V

DDDDK)

IVGGY

E-Elastase

'`'`'

`'`'`

'`'`'

VVGGT

-

x

30

35

36ABC37 40

45

C

EAPVG

SWPWQ

DK'`'TGTH

FCGGS

T

TCGAN

TVPYQ

'`'`'SGYH

FCGGS

E

EAQRN

SWPSQ

ISLQYRSGSWAH

TCGGT

- Section showing histidine 57: -

x

46-50

55

56,57-60

65

65A 66-70

C

LINEN

WVVTA

AHCGV

TTSDV

'VVAGEFD

T

LINSQ

WVVSA

AHCYK

SGIQV

RL'`GQDN

E

LIRQN

WVMTA

AHCVD

RELTF

RVVVGEHN

-

x

73-75-80

85

90

95

96-99A

C

QGSSSEKI

QKLKI

AKVFK

NSKYN

SLTI'

T

INVVEGNQ

QFISA

SKSIV

HPSYN

SNTL'

E

LNQNNGTE

QYVGV

QKIVV

HPYWN

TDDVA

-

x

99B 102,3,4,5

106-110

115

120

121 5,126

C

'NNDITL

LKLST

AASFS

QTVSA

VCLPSA

T

'NNDITL

IKLKS

AASLN

SRVAS

ISLPT'

E

AGYDIAL

LRLAQ

SVTLN

SYVQL

GVLPRA

-

Remaining half of the sequence, 127-245, not shown. (site serine 195, not shown)

See also

  • Amino acid
  • Catalytic triad

References

  • Wilson, Eisner, Briggs, Dickerson, Metzenberg, O'Brien, Susman, & Boggs. Life on Earth, Edward O. Wilson, Thomas Eisner, Winslow R. Briggs, Richard E. Dickerson, Robert L. Metzenberg, Richard D. O'Brien, Millard Susman, William E. Boggs, c 1973, Sinauer Associates, Inc., Publisher, Stamford, Connecticut. 1033 pp, 19 p Index & Back Page (hardcover, ISBN 0-87893-934-2)