Packing head-to-tail

In the solid state, the nanotube units 45 (n = 1, Fig. 19) pack head to tail, in straight rows, resulting in infinitely long cylinders (82). The neighboring nanocylinders aligned parallel to each other (Fig. 20). In each nanocylinder, molecules 45 are twisted by 90° relative to each other, and the Ar—O—Pr... 

The nucleus initiates the packing of the tubulin dimer into protofibrils, and the intaa MTs generated are stractaraUy and kinetically asymmetric. Tubulin dimers pack head-to-tail, generating polymers with distina ends. The plus end of the MTs is that from which both growth and disassembly occur more rapidly under physiological conditions. 

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