keytest2

keytest2 - BCH 4053 February 28, 2003 (10) 1. HOUR TEST 2...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
February 28, 2003 HOUR TEST 2 NAME______ KEY _________ (10) 1. Describe two methods of cleaving disulfide bonds prior to sequencing a protein, indicating the reagents used in each case and the structure of the cysteine residue produced after the cleavage. 1 pt rxn, 2 pts reagent(s), 2 pts cysteine derivative structure (a) Performic acid oxidation + HCOOOH -SO 3 - -SO 3 - + H 3 N CH C CH 2 O O SO 3 - cysteine derivative: Page Points 1 _ 22 _ 2 _ 30 _ 3 _ 25 _ 4 _ 23 _ Total __ 100 _ -S-S- (b) Reduction followed by alkylation + 2 RSH RSSR + -SH -SH -SCH 2 COO - -SCH 2 COO - + ICH 2 COO - or ICH 2 CONH 2 -SCH 2 CONH 2 -SCH 2 CONH 2 + + + H 3 N CH C CH 2 O O SCH 2 COO - or H 3 N CH C CH 2 O O SCH 2 CONH 2 or cysteine derivative: (6) 2. A peptide was subjected to the following degradative techniques resulting in the fragments with the indicated sequences. I. Cyanogen bromide treatment Asp-Ile-Lys-Gln-Met Lys-Val-Ser Lys-Phe-Ala-Met Tyr-Arg-Gly-Met II. Trypsin hydrolysis Gln-Met-Lys Gly-Met-Asp-Ile-Lys Phe-Ala-Met-Lys Tyr-Arg Val-Ser Give the complete sequence of the original peptide. Tyr-Arg-Gly-Met-Asp-Ile-Lys-Gln-Met-Lys-Phe-Ala-Met-Lys-Val-Ser 6 pts complete sequence, 3 pts if all but one peptide aligned properly, 0 pts if more than one missed (6) 3. Fill in the following blanks with a helix or disordered to represent the primary conformation of the indicated synthetic polypeptide at the indicated pH. 1 pt each
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 07/22/2011 for the course BCH 4053 taught by Professor Logan during the Spring '06 term at FSU.

Page1 / 4

keytest2 - BCH 4053 February 28, 2003 (10) 1. HOUR TEST 2...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online