Proteases, ice and peptide bonds

Littlemore, Linda; Schober, Paul; Widmer, Fred

doi:10.1007/978-94-011-1474-5_55

Cited by 8 publications

(3 citation statements)

References 3 publications

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“…By surprise, when acetonitrile/carbonate buffer system (6 :4, pH 9) was used as the reaction medi um, the yield of coupling was much lower than in water and the cleavage products G lp '-H is 2-T rp3-S e r4-T y r 5-O H as well as G lp '-H is 2-T rp3-O H were detected by HPLC in the reaction mixture. These results show that the use of recom m ended solvent system does not ensure that the protease would act as a "synthetase" and this ob servation supports the suggestion o f Littlemore Brought to you by | MIT Libraries Authenticated Download Date | 5/12/18 3:40 AM et al [7] th at the ratio o f esterase and protease ac tivity o f enzyme depends also on other factors, for example the structure o f the reactants.…”

Section: Gnrh Via 5 + 5 Fragm Ent Couplingsupporting

confidence: 58%

Expedient Synthesis of Gonadotropin Releasing Hormone (GnRH) Through a Combined Chemical-Enzymatic Approach

Słomczyńska

Leplawy

Lepławy

1992

Zeitschrift Für Naturforschung B

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G onadotropin Releasing Hormone, Enzymatic Peptide Synthesis, Papain, a-Chym otrypsinWe have developed a chemical-enzymatic synthetic approach to gonadotropin releasing hormone G lp '-H is 2-T r p 3-S e r 4-T y r 5-G ly 6-L e u 7-A r g 8-P r o 9-G l y 10-N H 2 (G nR H ) which enables one to perform the synthesis efficiently according to minimal protection strategy with all reactive side chains o f amino acids unprotected. Five peptide bonds H is2-T r p 3, Tyr5-G l y 6, Leu7-A r g 8 and Trp3-S e r 4, S ei^-T yr5 were formed by means o f a-chym otrypsin and papain, respectively. The remaining four bonds G lp '-H is 2, Gly6-L e u 7, Arg8-P r o 9, Pro9-G l y 10 were formed by chemical methods. The synthesis is simple to carry out and there are no problems in scaling up as demonstrated by the final coupling on 2 g scale affording highly pure G nR H in the yield o f 8 4 -9 0 % .

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Section: Gnrh Via 5 + 5 Fragm Ent Couplingsupporting

confidence: 58%

Expedient Synthesis of Gonadotropin Releasing Hormone (GnRH) Through a Combined Chemical-Enzymatic Approach

Słomczyńska

Leplawy

Lepławy

1992

Zeitschrift Für Naturforschung B

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“…As already outlined for supercritical fluids, the size of equipment and the high capital and operating costs connected with the freezing process may by considered as general drawbacks of the frozen-state technology in particular for continuous large-scale syntheses. Finally, it should be noted that a couple of papers report on an unsuccessful use of frozen solutions in dipeptide synthesis indicating that the effects of freezing may not be generalized 4 Influence of Freezing on the Coupling of Specific Amino Acid-Containing Peptides Catalyzed by Trypsin, Bacillus L icheniformis Glu-Specific Endopeptidase (BL-GSE), and Chymotrypsin a yield (%) protease /acyl donoracyl acceptor25 °C−15 °CTrypsin Bz-Arg-OEt H-Ala−Ser-OH 12.0 93.5 H-Ala−Ala- Lys -Ala-Gly-OH 39.5 (51.3) 82.9 H-Ala−Ala- Arg −Ala−Gly-OH 39.9 (52.6) 89.9Chymotrypsin Ac-Tyr-OEt H-Gly−Leu-NH 2 69.6 97.5 H-Ala−Ala− Phe −Ala−Gly-OH 59.9 (68.8) 89.1 H-Ala−Ala− Tyr −Ala−Gly-OH 61.2 (71.3) 90.1BL-GSE Z-Glu-OMe H-Gly−Leu-NH 2 7.5 94.0 H-Ala−Ala- Asp −Ala−Gly-OH 8.0 94.5 H-Ala−Ala− Glu −Ala−Gly-OH 11.4 94.7 a According to ref .…”

Section: Synthesis In Nonconventional Mediamentioning

confidence: 99%

Proteases in Organic Synthesis

2002

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“…In the given case, the yields are at low reactant concentrations, 32% at − 10°C and 20% at 0°C, whereas at higher concentrations the yields are 19% at − 10°C and 28% at 0°C. After the pioneering work of Jakubke's group, similar peptide synthesis experiments also began in other laboratories [73,74]. Enzymic peptide synthesis in liquid.…”

Section: Review Articlementioning

confidence: 98%

Cryo-bioorganic chemistry: molecular interactions at low temperature

Vajda¹

1999

Cellular and Molecular Life Sciences (CMLS)

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Freezing of aqueous or organic solutions plays a pivotal role in enhancement of rate and/or yield of biomolecular reactions. The smooth conditions of the frozen state at low temperature can also suppress racemization and side-product formation of the reactions. Molecular interactions in liquid undercooled solutions, on the other hand, offer the possibility to study enzyme activity mechanisms in vitro and a chance for survival of organisms in vivo. This review illustrates the differences between frozen and liquid conditions on several small and large biomolecules, together with the synthetic use of freezing. In relation to the freezing effect on enzyme activity, a peculiar phenomenon is discussed: 'cryo-oscillations' are temporal motions of trypsin activity in frozen solution in the presence of Mn2+ ion. The molecular basis of cold adaptation is also discussed, which points to mechanisms evolved by organisms living at subzero temperatures. The factors involved in the freezing effect are shown; i.e. the role of freeze-concentration and frozen solvent surface is demonstrated and elucidated using several examples.

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Proteases, ice and peptide bonds

Cited by 8 publications

References 3 publications

Expedient Synthesis of Gonadotropin Releasing Hormone (GnRH) Through a Combined Chemical-Enzymatic Approach

Expedient Synthesis of Gonadotropin Releasing Hormone (GnRH) Through a Combined Chemical-Enzymatic Approach

Proteases in Organic Synthesis

Cryo-bioorganic chemistry: molecular interactions at low temperature

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