TITLE:
Structural, thermal and enzymatic analysis of naturally occurring and D-amino acid substituted peptides
AUTHORS:
Velmurugan Punitha, Raghava Rao Jonnalagadda, Balachandran Unni Nair
KEYWORDS:
Collagen-Like Peptide; Configurational Change; Leu-Gly-Pro-Ala; Collagen; Chirality; Amino Acid
JOURNAL NAME:
Advances in Bioscience and Biotechnology,
Vol.3 No.7,
November
28,
2012
ABSTRACT: Designing of new peptide materials for biomedical and protein engineering applications are important. In the present work an attempt has been made to study the effect of D-Leu in collagen like tetra peptide on the structure and stability of peptide against enzymes and results are compared with its chiral counterpart L-form. Effect of replacement of L-Leu in Leu-Gly-Pro-Ala tetra peptide with D-Leu on structure has been studied using circular dichroic spectroscopy (CD). Our findings suggest that, D-Leu substitution leads to conformational changes in Leu-Gly-Pro-Ala secondary structure from β-sheet to turns. L → D-Leu Configurational changes in Leu-Gly-Pro-Ala owes to enhanced thermal stability which has been substantiated through CD and differential scanning calorimetry. Change in chirality of the leucine inhibits collagenolytic activity, which enables to design selective inhibition of proteases with greater specificity.