Silkomics: Insight into the Silk Spinning Process of Spiders

The proteins from the silk-producing
glands were identified using
both a bottom-up gel-based proteomic approach as well as from a shotgun
proteomic approach. Additionally, the relationship between the functions
of identified proteins and the spinning process was studied. A total
of 125 proteins were identified in the major ampullate, 101 in the
flagelliform, 77 in the aggregate, 75 in the tubuliform, 68 in the
minor ampullate, and 23 in aciniform glands. On the basis of the functional
classification using Gene Ontology, these proteins were organized
into seven different groups according to their general function: (i)
web silk proteinsspidroins, (ii) proteins related to the folding/conformation
of spidroins, (iii) proteins that protect silk proteins from oxidative
stress, (iv) proteins involved in fibrillar preservation of silks
in the web, (v) proteins related to ion transport into and out of
the glands during silk fiber spinning, (vi) proteins involved in prey
capture and pre-digestion, and (vii) housekeeping proteins from all
of the glands. Thus, a general mechanism of action for the identified
proteins in the silk-producing glands from the Nephila clavipes spider was proposed; the current results also indicate that the
webs play an active role in prey capture.