PLP-Dependent Enzymes: Transformations and Biochemical Significance

PLP-Dependent Enzymes: Transformations and Biochemical Significance

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Your Name:

Imines are important biochemical functional groups that are utilized in several amino acid

metabolizing enzymes that require Pyridoxal 5’-phosphate (PLP), a vitamin B6-derived cofactor.

These enzymes are important especially in your brain as well as other organs. The enzymes work

by forming a stable imine in the protein active site between a lysine residue and PLP.

1. (a) For each general type of transformation indicated below, indicate a specific PLP-dependent

enzyme that will do each one. Then complete each scheme to show your peers the structure of the

generic amino acid that would be expected after each transformation. Include an actual scientific

literature reference for each. There are many scientific journals out there that can be referenced

but the reference should be of an actual paper published within the last 5 years. Your reference

should include: Journal Name, year, and First Author.

(i) Racemization

(iii) Decarboxylation

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(b) Choose one of your literature sources and write a very concise overview of the study. You

don’t need to get into all the technical aspects of the study but discuss what the goal of the study

was, the significance of the study (why is it important?), and what the big picture conclusions of

the study were. Make sure to include the reference of the paper you are writing a short synopsis

for.

When you are doing your two peer reviews, ask two questions that were not answered from the

synopsis you are reviewing. Then, ask for a response from these individuals that at least try to

address the questions you have asked.

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2. Draw an arrow-pushing mechanism illustrating how the imine forms between the enzyme lysine

and PLP. The structures below can be used as your starting point. In your reviews, comment on

any steps that you thing are incorrectly illustrated so they can be fixed.

BIDS(59)