L20 462a_hemoglobin3_lec20_2012

Calhydrogenbondin12interfacebetween2asn102and1

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: phobic patches. β Val6 This allows propagation of aggregation Formation of long, rigid insoluble fibers of HbS under conditions of low O2 Q: How is this different from amyloid-type aggregation? Lehninger Principles, Fig. 5-20b light blue = βS subunits DeoxyHbS aggregationred blood cell sickling Long fibers distort shape of red blood cells, sickleshaped cells clog capillaries, poking holes in cells (lysis), low [Hb], “sickle cell anemia” Sickled erythrocyte Berg, Tymoczko, & Stryer, Biochemistry, 6th ed. Fig. 7-23 Other mutant hemoglobins 2. muta:ons that lead to loss of heme, muta:ons in heme binding pocket Hb Hammersmith [βF42S]
 •  •  •  •  Phe
‐‐>
Ser
muta.on
 HbA:
Phe
blocks
access
 of
H2O
to
heme
pocket.

 smaller,
polar
Ser
 permits
H2O
to
enter.
 H2O
dislodges
heme
 from...
View Full Document

This note was uploaded on 01/22/2014 for the course BIOC 462A taught by Professor Ziegler,baldwin during the Winter '08 term at Arizona.

Ask a homework question - tutors are online