Preparation of [B23-d-alanine]des-(B25-B30)-hexapeptide-insulin by a combination of enzymic and non-enzymic synthesis

Enzymic synthesis of N-acetyl-D-mannosamine.

As repor ted earlier 1, an e n z y m e purif ied f rom Clostridium per#ingens (N-ace ty lneuramin ic acid aldolase; NaNaldolase) ca ta lyzes t he following reversible reac t ion: p y r u v a t e + N-acetyl-Dm a n n o s a m i n e (N-AcMm) ~ N-ace t y l neu rami n i c acid (sialic acid). The recogni t ion of N A c M m as a na tu ra l l y occurr ing suga r leads to t h e ques t ion of t he m e c h...

Enzymic formation of D-malate.

Tubbs & Greville (1961) showed that D-2hydroxy acid dehydrogenase (EC 1.1.2.4), present in liver and kidney in several animal species, catalyses the oxidation of D-lactate, D-malate and various straight-chain homologues. Similar NADindependent D-lactate dehydrogenases have been isolated from micro-organisms (Haugaard, 1959; de Ley & Schel, 1959; Snoswell, 1959; Nygaard, 1960). However, the meta...

Non-enzymic protein phosphorylation

Incubation of 6-phosphogluconate dehydrogenase from Candida utilis with either acetyl phosphate, 1,3-diphosphoglycerate or carbamoyl phosphate results in the phosphorylation of the protein. The binding of one phosphate residue per enzyme subunit does not affect significantly the kinetic properties, but makes the enzyme less reactive toward thiol reagents, trypsin and pyridoxal 5'-phosphate. We ...

The enzymic activation of D-alanine.

Enzymic Mechanism of Starch Synthesis in Plants

An important development in the field of polysaccharide biochemistry has been the discovery of starch synthetase in beans, potatoes and corn seedlings by Leloir and coworkers•>. The enzyme was found to be closely bound to the starch granules and to catalyze the transfer of glucose moiety from UDP-glucose into polysaccharides containing linkage of the a-D-(H4) type. Subsequently, the granule-bou...