If you discover a peptide that has a glycine at the N-terminus what can that tell you about peptide processing? O The peptide hormone must be processed from a precursor since all new proteins have a methionine at the N-terminus The N-terminus must be processed by methylation by adoMet O The peptide must be from bacteria since all bacterial peptides begin with the amino acid glycine O The N-terminus is phosphorylated by the action of an N-terminal kinase

A sample of an unknown peptide was divided into two aliquots. One aliquot was treated with trypsin and the other was treated with cyanogen bromide. Given the following sequences (N-terminal to C-terminal) of the resulting fragments, deduce the sequence of the original peptide. Trypsin treatment Asn—Tyr—Asp—Met—Phe—Ala—Arg Asp—Trp—Asn—Arg Gln—Met—Tyr—Cys—Pro—Ile—Arg Gln—Cys Cyanogen bromide treatment Tyr—Cys—Pro—Ile—Arg—Asn—Tyr—Asp—Met   Asp—Trp—Asn—Arg—Gln—Met Phe—Ala—Arg—Gln—Cys

What is the one-letter amino acid sequence formed from the following mRNA that codes for a pentapeptide that is an endorphin called Leu-enkephalin? 5' AUG - UAC - GGU - GGA - UUU - CUA - UAA 3'

In posttranslational modification, phosphates are attached to which 3 amino acids?  - tyrosine - serine - proline - lysine - threonine

Given the following diagram of how protein AWESOME1 binds to it's target DNA, describe the potential effects of each of the 5 mutations shown below. The wild-type sequence of a helix #1 is also shown in the blue box, and all the mutations are in helix #1 (see numbers for identifying particular residues). a helix #1 R(1)-V-I-L-Y-F-W-I-M-Y-F-S-H-Y-W-R(16) #1 Predict the consequence of the following mutations: 1) Arg(1) to Glu 2) Arg(1) to Ala 3) Phe(6) to lle 4) Trp(7) to Phe 5) Met(9) to Pro in

The coding sequence of insulin mRNA IS 330 nucieotide long When it is translated to palypeptides, how many amino acids wl the polypeptide contain? O 330 110 O 660

A researcher has synthesized two peptides and needs to confirm whether the peptides were synthesized with the correct sequence using mass spectrometry. What is the sequence of the b4 and y7 ions for peptide GAMECHANGER?  The peptide SLISRAEFLAGVRVGV is digested with trypsin. Then the products of the digestion are subjected to ESI TOF-MS in positive ion mode with the peptides in a pH 2 solution. What peptide fragments will result and what are their m/z?

5) Snake venom surprisingly has been a found to be a rich source of biologically active peptides. One important class of peptides includes the bradykinin potentiating peptides which were the precursors to today's most commonly used antihypertensive drugs such as captopril or lisinopril. Let's say that you are investigating a new peptide in the bradykinin potentiating peptide class from Agkistrodon bilineatus (Mexican pit viper) venom. You suspect that the peptide has the following sequence: QWAQGRAPHPP After some harrowing experiments, you've collected and isolated a sample of this peptide. How will you confirm that the sequence is what you expected? Describe a sequence of chemical tests (at least 4) that you can do on this peptide that should give you enough information to deduce the sequence. Be sure to describe in detail each of the chemical analyses and the expected results of each.