In order to examine the effect of hydrogen bond of the polypeptides on the growth mechanism of polypeptide crystals in the course of polymerization, the heterogeneous copolymerizations of L-proline N-carboxy anhydride(NCA) and L-valine NCA were studied in acetonitrile. In the polymerization systems with higher contents of L-proline NCA, the crystal growth occurs through formation of right handed helical structure of poly-L-proline I. Despite the fact that the crystal growth of β-structured polypeptide is known to proceed slowly through the formation of intramolecular hydrogen bonding, high conversion rate of nearly 90% was observed for the polymerization of L-valine NCA-rich system. It is postulated that L-proline residues were occluded into the poly-L-valine chain with β-structure, and the crystal growth occurs through formation of the cross-β structure as reported previously for poly-S-methyl-L-cysteine system.

α-아미노산무수물을 혼성중합시킬때 생성하는 polypeptide의 구조발생과정에서 수소결합의 영향을 검토하기 위하여 아세토니트릴중에서 L-proline NCA (N-carboxy-α-amino acid anhydride)와 L-valine NCA를 불균일계로 혼성중합시켰다. L-proline NCA가 많이 함유된 중합에서는 cis-구조를 가진 우선성의 poly-L-proline I의 나사선 구조로 결정이 성장하며, L-valine NCA가 많이 함유된 중합에서 분자간수소결합을 형성하는 β-구조로 폴리머의 결정이 성장함에도 불구하고 90%에 가까운 중합율을 가져왔다. 이 결정성장에서 L-proline은 poly-L-valine의 β쇄에 함유되어 결정이 성장하며 이때의 결정성장기구는 poly-S-methyl-L-cysteine에서 처럼 cross-β 구조를 형성하는 것으로 추측된다.