Poly[N‐(2‐hydroxypropyl)methacrylamide]s (PHPMAs) with one pendant cholesteryl moiety at the polymer end and two pendant cholesteryl moieties at both polymer ends as terminal groups (PHPMA‐Chol and PHPMA‐2Chol) were prepared by the radical polymerization of N‐(2‐hydroxypropyl)methacrylamide initiated with 4,4′‐azobis‐[(3‐cholesteryl) 4‐cyanopentanoate] in the presence of 2‐mercaptoethanol and thiocholesterol as chain‐transfer reagents, respectively. The self‐organization of the PHPMAs was analyzed by fluorescence and 1H NMR measurements. The critical micelle concentration (CMC) decreases with a decreasing PHPMA degree of polymerization. The CMC of PHPMA‐Chol is much larger than that of PHPMA‐2Chol. PHPMA exhibits an excellent blood compatibility, as determined from the Michaelis constant for the enzymatic reaction of thrombin and a synthetic substrate, S‐2238, in the presence of PHPMA‐2Chol. According to a small‐angle X‐ray scattering measurement, PHPMA‐2Chol can hold the cholesterol molecule as a lipophilic drug model in a hydrophobic layer formed by terminal‐located cholesteryl groups in PHPMA‐2Chol. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3369–3377, 2000

The 16-kDa rice allergen, RA17, belonging to the alpha-amylase/trypsin inhibitor family was isolated from rice seed and structurally characterized by identifying cystine-containing peptides and predicting the secondary structure and hydrophobic regions. Eight peptides, which constitute three sets of cystine-containing peptides, were purified by HPLC from a thermolytic digest of RA17 and identified by their amino acid sequence and composition, indicating five intramolecular disulfide bridges: Cys34-Cys94, Cys26-(Cys50 or Cys51)-Cys110 and Cys12-(Cys62 or Cys64)-Cys122. Analyses of the CD spectrum and the Chou-Fasman prediction suggested that RA17 had some helical- and sheet-structure regions. Based on these experimental and predicted data, RA17 is proposed to be a globular molecule with a small hydrophobic core having folding restricted by five intramolecular disulfide bridges.

Poly[9-(2-methacryloyloxyethyl)adenine] and poly [1-(2-methacryloyloxyethyl)thymine] with one pendant cholesteryl moiety at the polymer end (PMEA-Chol, PMETChol) and with two pendant cholesteryl moieties at both polymer ends as terminal groups (PMEA-2Chol, PMET-2Chol) were prepared by radical polymerization of 9-(2-methacryloyl-oxyethyl)adenine (MEA) and 1-(2-methacryloyloxyethyl)thymine (MET) initiated with 4,4 0 -azobis[(3-cholesteryl)-4-cyanopentanoate] in the presence of 2-mercaptoethanol or thiocholesterol as chain transfer reagents, respectively. The copolymers [PNiPAAm-co-PMEA-nChol (n ¼ 1,2)] composed of N-isopropylacrylamide (NiPAAm) and MEA were also prepared in a similar manner. The self-organization of these polymers and copolymers was confirmed by a fluorescence measurement, and then their critical concentrations of micelle formation (CMC) were determined. The mixture of PMEA-2Chol and cholesterol as a lipophilic drug model formed a lamella type of complex with an interplaner spacing of d ¼ 35.3 Å . The hypochromism based on the formation of a 1 : 1 interaction of adenine and thymine moieties was found to appear in the mixed aqueous solution of PMEA-Chol and PMET-Chol. Complementary interactions were also confirmed in the system of PMET-2Chol and adenosine as well as PMEA2Chol and uridine. Cis-dichlorodiammine platinum(II) (CDDP) was bound to PNiPAAm-co-PMEA-Chol through the adenine moiety by ligand substitution atoms of CDDP. The amount of CDDP loaded on the copolymer was found to be 0.143 g g À1 .

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