How can plasma cells make 2000 Immunoglobulins/sec?

I came across this astonishing figure in Kuby. It’s amazing. I don’t know about humans but in E.coli, 15 amino acids are translated per sec. Now an immunoglobulin molecule has more than 1200 amino acid residues.

Part of the answer involves the unfolded protein response. High protein synthesis requires very high activity in the ER. under high stress conditions, native proteins accumulate in the ER. Certain transmembrane proteins have receptors that detect increasing amounts of native protein accumulation and release factors which bind to these. It also secretes a large number of molecular chaperons which facilitate proper folding of the proteins.

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