Page 270 - Advances in Textile Biotechnology
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Low percentages of  glycine and alanine Low tensile strength  relative to drag line silks  but higher extensibility   and toughness  ECPs may function as   intermolecular   crosslinkers, with  potential structural roles    ber in the egg case fi  These two silks contain  very polar amino acids,  which include Ser, Asp,  Glu,








                           •   •


                 Blocks of GGX assumed to   form 3 10 -helices The spacer region is a highly  conserved and glycine-poor  sequence of 28 amino acids GGX domains are notably  different from other types of   Large ensemble repeats that  are 184 amino acids in length,  rich in serine but low in glycine Blocks of alanine and GGX  yield protein structures













                 •   •         silk proteins  •   •
                           Poly(S) blocks and   GGX  Poly(S), GX,   AAQAASAA,   AAAQA,   AASQAA and   SQ n  Short poly(A)   blocks and GA   repeats  Short poly(A)   blocks and GA   repeats  The precise   molecular   identities of the   proteins involved   remain to be   determined











                           AcSp1       TuSp1      ECP-1  ECP-2  Unknown  Unknown



                           Wrapping silk,   small-diameter    ber egg case fi  Large-diameter   egg case silk    ber  fi  Glue coating for   capture spiral  Attachment disc   and joining    ber  fi








                           Aciniform   Tubuliform             Aggregate  Pyriform








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