Franz Hofmeister


Franz Hofmeister 30 August 1850, Prague – 26 July 1922, Würzburg was an early protein scientist, and is famous for his studies of salts that influence the solubility and conformational stability of proteins Hofmeister was the first to propose that polypeptides were amino acids linked by peptide bonds in 1902, although this model of protein primary structure was independently and simultaneously conceived by Emil Fischer12

Contents

  • 1 Early life
  • 2 The Hofmeister series
  • 3 Protein purification
  • 4 Proposal of protein primary structure
  • 5 See also
  • 6 References
  • 7 External links

Early lifeedit

Hofmeister's father was a doctor in Prague, where Hofmeister first began his studies, under the physiologist Karl Hugo Huppert, himself a student of Carl Lehmann Hofmeister's Habilitationsschrift in 1879 concerned the peptic products of digestion

Hofmeister became a Professor of Pharmacology at the First Faculty of Medicine, Charles University in Prague in 1885, then eventually moved to Strasbourg in 1896

The Hofmeister seriesedit

Main article: Hofmeister series

Hofmeister discovered a series of salts that have consistent effects on the solubility of proteins and it was discovered later on the stability of their secondary and tertiary structure Anions appear to have a larger effect than cations, and are usually ordered

F − ≈ S O 4 2 − > H P O 4 2 − > a c e t a t e > C l − > N O 3 − > B r − > C l O 3 − > I − > C l O 4 − > S C N − \approx SO_^>HPO_^>acetate>Cl^>NO_^>Br^>ClO_^>I^>ClO_^>SCN^

This is a partial listing; many more salts have been studied The order of cations is usually given as

N H 4 + > K + > N a + > L i + > M g 2 + > C a 2 + > g u a n i d i n i u m ^>K^>Na^>Li^>Mg^>Ca^>guanidinium

The mechanism of the Hofmeister series is not entirely clear, but seems to result mainly from effects on the solvent at higher salt concentrations > 100 mM Early members of the series increase solvent surface tension and decrease the solubility of nonpolar molecules salt out; in effect, they strengthen the hydrophobic interaction By contrast, later salts in the series increase the solubility of nonpolar molecules salt in and decrease the order in water; in effect, they weaken the hydrophobic effect However, these salts also interact directly with proteins which are charged and have strong dipole moments and may even bind specifically eg, phosphate and sulfate binding to ribonuclease A Ions that have a strong salting in effect such as I− and SCN− are strong denaturants, because they salt in the peptide group, and thus interact much more strongly with the unfolded form of a protein than with its native form Consequently, they pull the unfolding reaction3 Moreover, they may have direct interactions with some standard hydrophobic molecules, eg, benzene

Protein purificationedit

The importance of the Hofmeister series to early protein work cannot be underestimated, since it provided the chief tool for purifying proteins sulfate precipitation over the next ~50 years, one that is still in use today Hofmeister himself may have been the first to crystallize a protein, hen egg-white albumin Repeated crystallization was a favorite purification technique in the early days of protein science, and was essential for its development

Proposal of protein primary structureedit

Hofmeister argued for peptide bonds by process of elimination C-C, ether and ester bonds were unlikely considering the digestion by trypsin R=C-N-C=R bonds could be eliminated because it would imply a much larger number of carboxylate groups than is observed experimentally

Hofmeister also argued for peptide bonds based on the biuret reaction observed with all proteins but never with free amino acids Since biuret has the formula NH2-CO-NH-CO-NH2, that suggested the presence of similar peptide bonds in proteins

See alsoedit

  • primary structure
  • peptide bond
  • Picture of Hofmeister at Science and Society site, UK
  • Hofmeister Still Mystifies, Chemical & Engineering News, July 16, 2012
See also: Hofmeister

Referencesedit

  1. ^ "Hofmeister, Franz" encyclopediacom Retrieved 4 April 2017 
  2. ^ "Protein, section: Classification of protein" britannicacom Retrieved 4 April 2017 
  3. ^ Baldwin RL 1996 "How Hofmeister ion interactions affect protein stability" Biophys J 71 4: 2056–63 Bibcode:1996BpJ712056B doi:101016/S0006-34959679404-3 PMC 1233672 PMID 8889180 
  • Hofmeister F 1888 Arch Exptl Pathol Pharmakol, 24, 247
  • Zhang, Y; Cremer, P December 2006 "Interactions between macromolecules and ions: The Hofmeister series" Current Opinion in Chemical Biology 10 6: 658–63 doi:101016/jcbpa200609020 PMID 17035073 
  • Zhou, Huan-Xiang October 2005 "Interactions of macromolecules with salt ions: an electrostatic theory for the Hofmeister effect" Proteins: Structure, Function, and Bioinformatics 61 1: 69–78 doi:101002/prot20500 PMID 16044460 
  • Tanford C and Reynolds J 2001 Nature's robots: a history of proteins, Oxford University Press ISBN 0-19-850466-7
  • Creighton TE 1993 Proteins, 2nd ed, W H Freeman ISBN 0-7167-2317-4
  • Jencks WP 1969 Catalysis in Chemistry and Enzymology, Dover republication 1987 ISBN 0-486-65460-5
  • Collins, KD; Washabaugh, MW 1985 "The Hofmeister effect and the behaviour of water at interfaces" Q Rev Biophys 18 4: 323–422 PMID 3916340 
  • John Leo, Abernethy 1967 "Franz Hofmeister - The impact of his life and research on chemistry" Journal of Chemical Education 44 3: 177 doi:101021/ed044p177 

External linksedit

  • Works by or about Franz Hofmeister at Internet Archive


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Franz Hofmeister

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