Chemical modification of bovine heart mitochondrial malate dehydrogenase. Selective modification of cysteine and histidine.

Reversible modification of pig heart mitochondrial malate dehydrogenase by pyridoxal 5'-phosphate.

1. Pig heart mitochondrial malate dehydrogenase incubated with pyridoxal 5'-phosphate at pH 8.0 and 25 degrees C gradually loses activity. Such inactivation can be largely reversed by dialysis or by addition of L-lysine or L-cysteine, and can be made permanent by NaBH4 reduction. 2. Modification of malate dehydrogenase with pyridoxal 5'-phosphate at 35 degrees C involves two phases, an initial ...

Selective chemical protein modification.

Chemical modification of proteins is an important tool for probing natural systems, creating therapeutic conjugates and generating novel protein constructs. Site-selective reactions require exquisite control over both chemo- and regioselectivity, under ambient, aqueous conditions. There are now various methods for achieving selective modification of both natural and unnatural amino acids--each ...

Physicochemical properties of pig and horse heart mitochondrial malate dehydrogenase.

Selective chemical modification of Escherichia coli elongation factor G. N-Ethylmaleimide modification of a cysteine essential for nucleotide binding.

Escherichia coli Elongation Factor G is inhibited ireversibly by the chemical modification of 1 cysteine residue with N-ethylmaleimide. At pH 5.2, this cysteine is approximately 130 times more reactive than beta-mercaptoethanol toward N-ethylmaleimide. Inhibition is not prevented by either the ribosome or GTP alone at concentrations approximately equal to that of Elongation Factor G, but in com...

modification of nanoclay for improving the physico-mechanical properties of dental adhesives

هدف اصلی این مطالعه تهیه یک سامانه نوین چسب عاجی دندانی بر پایه نانورس پیوند شده با پلی متاکریلیک اسید، نانورس پیوند شده با پلی اکریلیک اسید، مخلوط نانوسیلیکا و نانورس پیوند شده با پلی متاکریلیک اسید، مخلوط نانوسیلیکا و نانورس پیوند شده با پلی اکریلیک اسید و نانورس پیوند شده با کیتوسان اصلاح شده با گلایسیدیل متاکریلات است. پیوند پلی متاکریلیک اسید و پلی اکریلیک اسید بر ری سطح نانورس در حضور و ...