Peptide vaporization

DCC is a waxy solid that is often difficult to remove from a bottle. Its vapors are extremely hazardous to inhalation and to the eyes. It should always be handled in a fume hood. The isourea by-product of a DCC-initiated reaction, dicyclohexyl urea (DCU) (Figure 3.5), is also water-insoluble and must be removed by organic solvent washing. For synthesis of peptides or affinity supports on insoluble matrices this is not a problem, because washing of the support material can be done without disturbing the conjugate coupled to the support. For solution phase chemistry, however, reaction products must be removed by solvent washings, precipitations, or recrystallizations. 

Fig. 9. X-ray intensity distributions (arbitrary scale) from aggregates formed by different polyglutamine peptides (Q , for n = 8,15, 28, 45) polyGln45 (dried), polyGln28 (vapor hydrated), polyGln15 (vapor hydrated), and polyGlng (lyophilized). The vertical bars indicate the positions of the Bragg reflections. The first interference peak for slab stacking of Q8 is indicated by. See Sharma et al. (2005) for further details.

Jarrold M.F. (2000), Peptides and proteins in the vapor phase, Annu. Rev. Physical Chem. 51, 179-207. 

Wolfenden, R. V. Interaction of the peptide bond with solvent water a vapor phase analysis. Biochemistry, 17(1) 201-204,1978. 

A Tsugita, T Uchida, HW Mewes, T Ataka. Rapid vapor-phase acid (hydrochloric acid and trifluoroacetic acid) hydrolysis of peptide and protein. J Biochem 102 1593-1597, 1987. 

Add fresh glutaraldehyde to the peptide/carrier solution to obtain a 1% final concentration. Mix well. Caution Use of a fume hood is recommended when working with glutaraldehyde. Avoid contact with skin and clothing. Do not breathe vapors. 

Bray AM, Jhingran AG, Valerio RM, Maeji NJ, Simultaneous multiple synthesis of peptide amides by multipin method. Application of vapor-phase ammonolysis, J. Org. Chem., 59 2197-2203, 1994. 

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