Draw the structure of the predominant form of pyridoxal-

5-phosphate at pH 7.00

Pyridoxal phosphate (PLP, pyridoxal-5-phosphate, P5P), the active form of vitamin B6, is a coenzyme in a variety of enzymatic reactions. The International Union of Biochemistry and Molecular Biology has catalogued more than 140 PLP-dependent activities, corresponding to ~4% of all classified activities. The versatility of PLP arises from its ability to covalently bind the substrate, and then to act as an electrophilic catalyst, thereby stabilizing different types of carbanionic reaction intermediates.

In this task we will draw the structure of predominant form of pyridoxal-5-phosphate (PLP) at pH=7.00

Only NH has a value of ${\mathrm{pK}}_{\mathrm{a}}$>7.00 so it would not be deprotonated at pH=7.00 and rest of residues would be because their ${\mathrm{pK}}_{\mathrm{a}}$< 7.00

The structure of PLP at pH=7.00 :