Proteolytic stability of beta-peptide bonds probed using quenched fluorescent substrates incorporating a hemoglobin cleavage site.
A set of designed internally quenched fluorescence peptide substrates has been used to probe the effects of insertion of beta-peptide bonds into peptide sequences. The test sequence chosen corresponds to a proteolytically susceptible site in hemoglobin alpha-chain, residues 32-37. Fluorescence and mass spectral measurements demonstrate that the insertion of an beta-residues at the potential cleavage sites completely abolishes the action of proteases; in addition, the rate of cleavage of the peptide bond preceding the site of modification is also considerably reduced.
Gopi
Hosahudya N
HN
Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India.
Ravindra
Gudihal
G
Pal
Prajna P
PP
Pattanaik
Priyaranjan
P
Balaram
Hemalatha
H
Balaram
Padmanabhan
P
D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000737:chemistry; D001665:Binding Sites / Q000502:physiology; D002918:Chymotrypsin / Q000737:chemistry; D019286:Endopeptidase K / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry*; D006454:Hemoglobins / Q000737:chemistry*; D009282:Naphthalenesulfonates / Q000737:chemistry; D010434:Pepsin A / Q000737:chemistry; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D010963:Plasmodium falciparum / Q000201:enzymology; D015800:Protozoan Proteins; D013050:Spectrometry, Fluorescence; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013379:Substrate Specificity; D014357:Trypsin / Q000737:chemistry; D004124:p-Dimethylaminoazobenzene / Q000031:analogs & derivatives* / Q000737:chemistry
D005456:Fluorescent Dyes; D006454:Hemoglobins; D009282:Naphthalenesulfonates; D010455:Peptides; D015800:Protozoan Proteins; C063127:4-(4-dimethylaminophenylazo)benzoic acid; C006421:1,5-I-AEDANS; D004124:p-Dimethylaminoazobenzene; D002918:Chymotrypsin; D014357:Trypsin; D019286:Endopeptidase K; D016282:Aspartic Acid Endopeptidases; D010434:Pepsin A; C100637:plasmepsin II