물-알코올 용액에서 염기성으로 작용하는 폴리펩타이드와 산성으로 작용하는 폴리펩타이드 사이에 수소결합을 통한 복합체 형성에 관한 연구를 점도, PH, 빛산란, 원편광이색성, 광회전도 등으로 조사했다. 얻어진 결과는 여러가지 복합체 시스템 모두가 1:2 조성으로 복합체 형성을 한다는 것을 알 수 있었으며, 우선성 헬릭스를 가지는 폴리펩타이드와 좌선성 헬릭스를 가지는 폴리펩타이드, 즉 반대방향성의 헬릭스 구조를 가지는 폴리펩타이드들 사이에 강한 상호작용을 나타내고, 반면, 같은 방향성의 헬릭스 구조를 가지는 폴리펩타이드의 형태가 복합체 형성에 매우 중요한 역할을 한다는 것을 나타낸다. 즉, 입체선택적 복합체 형성을 보인다. 또한 구조적으로 유연한 구조를 가지는 폴리펩타이드가 강한 상호 작용을 나타낸다. 즉, PHPL보다 PLP(I)이, PLP(I)보다 PLP(II)가, PAA보다 PGA가 더 강한 상호작용을 나타낸다. 이런 상호 복합체 형성이 일어나면 형태전이가 일어난다는 것도 확인할 수 있었다. 위의 결과를 근거로 하여, 좌선성 헬릭스 구조의 모발의 케라틴에 PLP(I, II)와 PHLP를 흡착시킨 후, 흡착량을 HPLC로 측정한 결과, PLP(II)보다 PLP(I)이, PHLP보다 PLP(II)가 더 많이 흡착되었다. 결론적으로, 모발에 폴리펩타이드를 사용시, 좌선성헬릭스 구조의 폴리펩타이드 보다 우선성헬릭스 구조의 폴리펩타이드가 더 많이 흡착되고, rigid conformation의 폴리펩타이드보다 foexible conformation의 폴리펩타이드가 더 많이 모발에 흡착되어, 효과가 좋다는 것을 알 수 있다.
Polypeptide has been used broadly as an active ingredient in cosmetics We thought it is very important to investigate the adsorption behavior of polypeptide in order to pre-estimate the effect of these polypeptides. For the study of polypeptide adsorption, we have investigated complex formation of basic homopolypeptides, poly(L-proline) Form I [PLP(I)], Form II [PLP(II)] and poly(4-hydroxy-L-proline) (PHLP) with acidic homopolypeptides, poly(L-glutamic acid) (PLGA), poly(D-glutamic acid) (PDGA) and poly(L-aspartic acid) (PLAA) through hydrogen bonding in a hydroalcoholic medium with viscometer, 1ight scatter, pH meter and circular dicroism (CD). The polypeptides used in this study have helical structure in some conditions. The result exhibited that al 1 the complexes were formed as the composition of basic/acidic homopolypeptide : L:2 irrespective of the complex systems used. A more favorable complex is formed in the PLP(II)-PLGA system than PHLP-PLGA because PLP(II) has a more flexible helical conformation, whereas PHLP has a more rigid helical conformation. The right-handed helix PLGA formed the complex favorably and quickly with the left-handed helix PLP(II), whereas the left-handed helix PDGA formed the complex favorably with the right-handed helix PLP(I). The effect of side chain of the acidic homopolypeptides on the complexation was also studied. The result showed that more favorable condition for the complexation was PLGA-PLP(II) system which has longer side chain at acidic homopolypeptide than PLAA - PLP(II). All the above facts were well supported by CD measurement for the complex systems. By the CD spectra for the complexes we could deduce the conformational change of each homopolypeptide in the complexes On the basis of the above results, we performed the adsorption test of PLP(I, II) and PHLP on the hair having a left-handed helix. The adsorption amount of each polypeptide was analyzed by HPLC. The result showed that PLP(I) was adsorbed more than PLP(II), PLP(II) was adsorbed more than PHLP on the hair. On adsorbing polypeptides having a helical structure on the hair through hydrogen bonding, it could be concluded that the helical polypeptides having the opposite directional structure to the hair are adsorbed more than those having the same directional structure with the hair and also the polypeptides having a flexible conformation are adsorbed more than those having a rigid conformation
