Seminars
Last F John Antos
Protein Engineering of Sortases
and transacylase reactions
Page 603
Figure 17-24
Reaction
mechanism of
lactate
dehydrogenase.
Page 604
Figure 17-25 The two
reactions of alcoholic
fermentation.
Page 604
Figure 17-26 Thiamine
pyrophosphate.
Figure 23-3a Biotin and carboxybiotinyl–
enzyme. (a) Biotin consists of an imidazoline ring
that is cis-fused to a tetrahydrothiophene ring
bearing a valerate side chain.
Raw eggs contain avidin—a protein with
very high affinity for biotin
Bacteria (Streptomyces) make avidin
analogs like streptavidin—where did we
see this recently???
http://www.rpi.edu/dept/bcbp/molbiochem/MBWeb/mb1/part2/chime/biotin/btn-index.html
Pentose Phosphate Pathway!
Cells’ second energy currency:
NADPH!
•
NADPH is required for reductive biosynthesis
–
–
–
–
•
FA’s
Steroids
Photosynthesis
Etc.
Most cells maintain their [NAD+]/[NADPH] near 1000!!!
NADPH is generated by oxidation of G6P
– Pentose phosphate pathway (PPP) = hexose monophosphate shunt= phosphogluconate
pathway
– 3 G6P + 6 NADP+ + 3 H2O →6 NADPH + 6 H+ + 3 CO2 + 2 F6P = GA3P
•
Pathway divided into 3 phases
– Oxidative Reactions
• Produces Ribulose-5-P
– Isomerization/Epimerization Reactions
• Produces Ribose-5-P and Xyulose-5-P
– Transaldolase and Transketolase Reactions
• 3 Ru5P ↔r5P + 2 Xu5P
Page 863
Figure 23-25 The pentose phosphate pathway.
FIGURE 14-27 Role of
NADPH in regulating the
partitioning of glucose 6phosphate between
glycolysis and the pentose
phosphate pathway. When
NADPH is forming faster
than it is being used for
biosynthesis and glutathione
reduction (see Figure 1420), [NADPH] rises and
inhibits the first enzyme in
the pentose phosphate
pathway. As a result, more
glucose 6-phosphate is
available for glycolysis.
PPP Song
Lyrics
• http://books.google.com/books?id=oq9EN
yL_d9YC&lpg=PP1&pg=PA1#v=onepage
&q&f=false
http://books.google.com/books?id=oq9ENyL_d9YC&lpg=PP1&pg=PA1#v=one
page&q&f=false
David L. Nelson and Michael M. Cox
• LEHNINGER
• PRINCIPLES OF
BIOCHEMISTRY
• Fifth Edition
CHAPTER 15
Principles of Metabolic Regulation
© 2008 W. H. Freeman and Company
“Alfonse, Biochemistry makes my head hurt!!”
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