Mechanism of spider silk formation.
A major ampullate spider silk gland from the spider Nephila clavipes. The conditions determined along the gland, a drop in pH from 7.6 to <5.7 and increased CO2 pressure, cause the synchronous molecular events of a lock and trigger mechanism that govern the silk fiber formation. The broad pH gradient is generated by carbonic anhydrase that is present in a distinct part of the gland. See Andersson et al.
Image Credit: Marlene Andersson