Department of Organic Chemistry Eotvos Lorand University Budapest, Hungary
Published at the
THIRTEENTH AMERICAN PEPTIDE SYMPOSIUM EDMONTON ALBERTA CANADA
PG.195 JUNE 20-25 1993.
In order to facilitate the discovery of new bioactive peptides we developed a new synthetic procedure.
Our Portioning-Mixing Method of Peptide Synthesis Introduced in 1988
The procedure is based on the Merrifield’s solid phase method.
The coupling cycles normally used in the solid phase synthesis are
Replaced by the following three operations:
1 Dividing the solid support into equal portions.
2 Coupling a different amino acid to each portion.
3 Mixing the portions.
Main Operations in a Coupling Cycle
1.9 grams of a dry Boc-aminoacyl resin mixture, the product of the previous coupling cycle, is weighed in equal portions into 19 reaction vessels. The resin samples are swollen in DCM, then submitted to deprotection (DCM-TFA 2:1) and washed (DCM, MeOH, DCM, MeOH, DCM, DCM). After deprotonation (DCM-EDIA 9:1) and washing with DCM each sample is submitted to coupling with a different activated Boc-amino acid (0.4 mmol each, dissolved in DCM/DMF 3:1). After adding the reagents the reaction vessels are turned into nearly horizontal position and shaken for 3 hours (Kaiser-test applied). After washing, the samples are transferred into the mixer, a mixture of DCM/DMF 2:1 is added, then the suspension mixed for 15 minutes, filtered and dried.
Simple Device for the manual synthesis of peptide libraries
Although the procedure is very simple, the synthesis of peptide libraries requires parallel treatment of about 20 samples (depending on the number of amino acids varied in a particular position).
In order to facilitate handling of the samples, a simple device has been constructed which is described in this presentation. The process of mixing also deserves some attention. A mixing chamber will also be presented.
Reaction Vessels on the Top of the vacuum chamber.
The reaction vessels are screw cap glass tubes (height 8 cm, internal diameter 1.2 cm) with a glass frit at the bottom. Polyethylene syringe tubes with frits are also used.
The lower outlet part of the reaction vessels is inserted into the hole of the vacuum chamber. The aluminum tube can be turned around its long axis so the reaction vessels can be fixed in any position between vertical (for washing) and horizontal (while shaking). The two positions are seen on two photos.
Dual Mixer Chamber
Department of Organic Chemistry Eotvos Lorand University Budapest, Hungary 1992
The mixer is a polyethylene vessel with 6 gas inlet tubes mounted at the bottom. The suspension of resin beads is mixed by the bubbling nitrogen gas entering through frits.
Description of the Vacuum Chamber
The device is a vacuum chamber mounted on a shaker. It is made of an aluminum tube (length 24 cm, diameter 8 cm, wall thickness 0.5 cm). Both ends of the tube have removable threaded end caps.
Theoretical schematic of the peptide synthesizer
On one side of the vacuum chamber are 20 holes with rubber rings in them to hold strongly the reaction vessels and support a vacuum.
One of the end caps of the tube has an outlet connected to a water pump.
The synthesis is so effective that millions, or even billions of peptides could be synthesized in a week by using the simplest manual method.
This method revolutionized pharmaceutical research, brought about a completely new way of thinking into the field of "peptide synthesis" and radically changed the strategy of future research.
This was followed by hundreds of researches bringing about a rapid development of a new field within chemistry. The original name of "synthesis of peptide libraries" is currently referred to as "combinatorial chemistry". "Combinatorial chemistry" is scientific, efficient and highly economical. With Its new name and terminology, it seems to have taken on a different identity since the original apparatus called "a simple device" was introduced in Edmonton, Alberta, Canada in 1993. Numerous automatic models have stemmed from this bench top model called "a simple device" by its inventor some thirteen years ago. It seems as though no one in the scientific community remembers or is even aware of the originator of this invention.