Question

Which of the following is incorrect regarding the Protein Identification through Database Searching?

(a) MS characterization of proteins is highly dependent on bioinformatic analysis

(b) Bioinformatics programs can be used to search for the identity of a protein in a database of theoretically digested proteins

(c) Even in reality, the protease digestion is always perfect in MS

(d) The purpose of the database search is to find exact or nearly exact matches

The question was posed to me by my school principal while I was bunking the class.

Question is from Technology of Protein Expression Analysis in division Functional Genomics & Proteomics of Bioinformatics

Answer 1

Correct answer is (c) Even in reality, the protease digestion is always perfect in MS

Easiest explanation: In reality, protease digestion is rarely perfect, often generating partially digested products as a result of missed cuts at expected cutting sites. Peptides resulting from MALDI-MS are also charged, which increases their mass slightly.