***********************************
* Spermadhesins family signatures *
***********************************

A family  of  mammalian  sperm  proteins  has been recently characterized [1].
The proteins that are currently known to belong to this family are:

 - Pig spermadhesins AQN-1, AQN-3 and AWN-1. These proteins are synthesized by
   the sexual  accessory  glands  and becomes attached to the sperm surface at
   the time  of  ejaculation. They bind to the ZP-glycoproteins and to heparin
   and seems to inhibit serine protease inhibitors.
 - Bovine acidic seminal fluid protein (ASFP), which seems to be growth factor
   with effects on ovarian granulosa cells.
 - Pig major seminal plasma glycoprotein PSP-I.

As shown in the following schematic representation these proteins,  which have
from 110 to 130 amino acid residues, contain four conserved cysteines involved
in two disulfide bonds.

                +---------+           +---------+
                |         |           |         |
            xxxxCxxxxxxxxxCxxxxxxxxxxxCxxxxxxxxxCxxxxxxxxxxxxxxxxxx
                ************          ***********

'C': conserved cysteine involved in a disulfide bond.
'*': position of the patterns.

-Consensus pattern: C-G-G-x-L-x(4)-G-x(11)-C-[LIVM]-W-T
                    [The two C's are involved in a disulfide bond]
-Sequences known to belong to this class detected by the pattern: ALL.
-Other sequence(s) detected in SWISS-PROT: NONE.

-Consensus pattern: C-x-K-E-x-[LIVM]-E-[LIVM]-x-[DE]-x(3)-G-x(5)-K-x-C
                    [The two C's are involved in a disulfide bond]
-Sequences known to belong to this class detected by the pattern: ALL.
-Other sequence(s) detected in SWISS-PROT: NONE.
-Last update: June 1994 / First entry.

[ 1] Calvete J.J., Solis D., Sanz L., Diaz-Maurino T., Schaefer W.,
     Mann K., Toepfer-Petersen E.
     Eur. J. Biochem. 218:719-725(1993).