Effect of sequence on the ionization behavior of a series of amphiphilic polypeptides

The behavior of five polypeptides made of hydrophilic and pH-responsive aspartic acid (Asp) and hydrophobic phenylalanine (Phe), which had been prepared by stitching together short well-defined sequences of Asp and Phe, was studied as a function of pH. The effect of pH on these polypeptides referred...

Ausführliche Beschreibung

Bibliographische Detailangaben
Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1999. - 29(2013), 14 vom: 09. Apr., Seite 4451-9
1. Verfasser: Fowler, Michael (VerfasserIn)
Weitere Verfasser: Siddique, Bushra, Duhamel, Jean
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2013
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article Research Support, Non-U.S. Gov't Peptides Pyrenes Surface-Active Agents Water 059QF0KO0R pyrene 9E0T7WFW93
LEADER 01000naa a22002652 4500
001 NLM225747316
003 DE-627
005 20231224065846.0
007 cr uuu---uuuuu
008 231224s2013 xx |||||o 00| ||eng c
024 7 |a 10.1021/la400030j  |2 doi 
028 5 2 |a pubmed24n0752.xml 
035 |a (DE-627)NLM225747316 
035 |a (NLM)23484851 
040 |a DE-627  |b ger  |c DE-627  |e rakwb 
041 |a eng 
100 1 |a Fowler, Michael  |e verfasserin  |4 aut 
245 1 0 |a Effect of sequence on the ionization behavior of a series of amphiphilic polypeptides 
264 1 |c 2013 
336 |a Text  |b txt  |2 rdacontent 
337 |a ƒaComputermedien  |b c  |2 rdamedia 
338 |a ƒa Online-Ressource  |b cr  |2 rdacarrier 
500 |a Date Completed 20.09.2013 
500 |a Date Revised 21.11.2013 
500 |a published: Print-Electronic 
500 |a Citation Status MEDLINE 
520 |a The behavior of five polypeptides made of hydrophilic and pH-responsive aspartic acid (Asp) and hydrophobic phenylalanine (Phe), which had been prepared by stitching together short well-defined sequences of Asp and Phe, was studied as a function of pH. The effect of pH on these polypeptides referred to as (Asp3Phe1)n, (Asp2Phe1)n, (Asp1Phe1)n, (Asp1Phe2)n, and (Asp1Phe3)n varied dramatically depending on their constituting sequence. The more hydrophobic polypeptides (Asp1Phe2)n and (Asp1Phe3)n behaved as if the Asp's were isolated from each other and showed an apparent pKa (pKa(app)) that remained constant with level of ionization (α = [Asp(-)]/[Asp]total) and equaled 5.4 and 6.4, respectively. The more hydrophilic polypeptides (Asp3Phe1)n and (Asp2Phe1)n behaved like weak polyacids showing a linear increase in pKa(app) with increasing α. The pKa(app) of (Asp1Phe1)n showed a trend as a function of α intermediate between the Asp-rich and Phe-rich polypeptides, behaving as if the Asp's were isolated at low α values (<0.35) but acting as a weak polyacid for large α values (>0.35). The effect that α, and thus the charge density of the polypeptides, had on the collapse and aggregation of the polypeptides was characterized by conducting static light scattering and fluorescence measurements. Static light scattering measurements demonstrated that all polypeptides precipitated and aggregated in solution at a critical charge density of 0.2. Fluorescence measurements with pyrene indicated that this behavior was due to the formation of Phe aggregates in water. Together, these experiments provide a complete description of how pH affects the behavior of a series of unique amphiphilic polypeptides designed with a well-defined sequence 
650 4 |a Journal Article 
650 4 |a Research Support, Non-U.S. Gov't 
650 7 |a Peptides  |2 NLM 
650 7 |a Pyrenes  |2 NLM 
650 7 |a Surface-Active Agents  |2 NLM 
650 7 |a Water  |2 NLM 
650 7 |a 059QF0KO0R  |2 NLM 
650 7 |a pyrene  |2 NLM 
650 7 |a 9E0T7WFW93  |2 NLM 
700 1 |a Siddique, Bushra  |e verfasserin  |4 aut 
700 1 |a Duhamel, Jean  |e verfasserin  |4 aut 
773 0 8 |i Enthalten in  |t Langmuir : the ACS journal of surfaces and colloids  |d 1999  |g 29(2013), 14 vom: 09. Apr., Seite 4451-9  |w (DE-627)NLM098181009  |x 1520-5827  |7 nnns 
773 1 8 |g volume:29  |g year:2013  |g number:14  |g day:09  |g month:04  |g pages:4451-9 
856 4 0 |u http://dx.doi.org/10.1021/la400030j  |3 Volltext 
912 |a GBV_USEFLAG_A 
912 |a SYSFLAG_A 
912 |a GBV_NLM 
912 |a GBV_ILN_22 
912 |a GBV_ILN_350 
912 |a GBV_ILN_721 
951 |a AR 
952 |d 29  |j 2013  |e 14  |b 09  |c 04  |h 4451-9