What is the net charge of a sT-loop at pH 7.2?

What is the net charge of a sT-loop at pH 7.2?

• A. -2
• B. -1
• C. 0
• D. +1

Answer: (C)

To determine the net charge of a sT-loop at pH 7.2, it's essential to consider the ionizable groups present in the peptide sequence that characterizes a sT-loop. At physiological pH, which is around 7.2, the side chains of certain amino acids will either be positively charged, negatively charged, or neutral based on their pKa values. The carboxylic acid side chains (like aspartate and glutamate) will typically be negatively charged at this pH due to their pKa values being lower than 7.2. Conversely, side chains of basic amino acids (like lysine and arginine) will be positively charged at this pH, as their pKa values are above 7. When evaluating a typical sT-loop structure, one would usually find that the predominant ionizable groups contribute to a balance of positive and negative charges. If the total contributions of the negatively charged side chains and positively charged side chains are equal, it would result in a net charge of zero. In this case, assuming that the specific sequence of the sT-loop does not favor significant positive or negative contributions at pH 7.2, the net charge can indeed be zero, as

To determine the net charge of a sT-loop at pH 7.2, it's essential to consider the ionizable groups present in the peptide sequence that characterizes a sT-loop.

At physiological pH, which is around 7.2, the side chains of certain amino acids will either be positively charged, negatively charged, or neutral based on their pKa values. The carboxylic acid side chains (like aspartate and glutamate) will typically be negatively charged at this pH due to their pKa values being lower than 7.2. Conversely, side chains of basic amino acids (like lysine and arginine) will be positively charged at this pH, as their pKa values are above 7.

When evaluating a typical sT-loop structure, one would usually find that the predominant ionizable groups contribute to a balance of positive and negative charges. If the total contributions of the negatively charged side chains and positively charged side chains are equal, it would result in a net charge of zero.

In this case, assuming that the specific sequence of the sT-loop does not favor significant positive or negative contributions at pH 7.2, the net charge can indeed be zero, as