Synthesis of the sequential polypeptide poly[Cys(Acm)-Ser-Phe-Glu-Glu] as a model for hydrolytic enzymes.
To construct a possible model of hydrolytic enzymes, the sequential polypeptide H[Cys(Acm)-Ser-Phe-Glu-Glu]nOH, n = 3-110, was prepared by polycondensation of H-Cys(Acm)-Ser(But)-Phe-Glu(OBut)-Glu(OBut)-O Su/1-hydroxybenzotriazole. In a solid state the polypeptide material showed beta-conformation both before and after cleavage of t-butyl protecting groups. The pentapeptide unit was synthetized by the Merrifield method utilizing modifications as follows: Gel phase synthesis on less than 0.5% cross-linked copolystyrene (quasi dissolved state). Centrifugal reactor. Ddz-amino acids, deprotected by 5% trifluoroacetic acid/dichloromethane/15 min. 3-Nitrophthalic anhydride to suppress formation of false sequences. Continuous photometric control of the completion of all operations during synthesis and transesterfication, yielding Ddz-Cys(Acm)-Ser(But)-Phe-Glu-(OBut)-Glu(OBut)-OMe (0.827 g; 53%, m.p. 180-182 degrees).
D000595:Amino Acid Sequence; D006867:Hydrolases / Q000032:analysis / Q000138:chemical synthesis*; D009682:Magnetic Resonance Spectroscopy; D010455:Peptides / Q000032:analysis / Q000138:chemical synthesis*; D013055:Spectrophotometry, Infrared
D010455:Peptides; D006867:Hydrolases