I did find this from the University of Vanderbilt:
http://www.vanderbilt.edu/ans/psycho...in.htm#PROTEIN AND ATHLETES
PROTEIN AND ATHLETES
What evidence is there to support or disprove claims that high intake levels of protein help build muscle mass and better athletes? Muscles are made mostly of protein, so logically one would think that the more protein in the diet, the more muscle one should have. Certain types of exercise, weight lifting for example, do stimulate muscle growth. So, a combination of weight training and large amounts (the more, the better) should be beneficial, right? Not exactly. The most recent indications are that dietary protein in excess of the current recommended dietary allowance (0.8 grams of protein per kilogram of body weight per day) is likely needed for optimal muscle growth (5.) "The current recommended dietary allowance doesn't seem to be enough for elite athletes who are training every day, who are growing, or who are training especially hard right before an event" (6.) However, the benefit appears to plateau at intakes well below the levels typically consumed by many athletes. Thus, for best results, a diet high in protein is beneficial for muscle growth, but only to an extent. Once a certain intake level is reached, any additional protein taken in will not help build muscle mass any more.
A study done by Fern et. al (1991) showed that greater gains in body mass occur over four weeks of heavy weight training when young men consumed 3.3 versus 1.3 grams if protein per kilogram of body mass. In addition a study done by Meredith et al. (1992) found that a daily dietary supplement containing 23 grams of protein combined with weight training can enhance muscle mass gains relative to similar subjects who trained with out the supplement. Both of the studies show support for the belief that increased protein in the diet can help increase muscle mass, but it should be noted that these effects were found with a combination of intake and training. These two studies further indicated that a protein intake of about 1.7 - 1.8 grams of protein per kilogram of body weight per day, when combined with weight training will enhance muscle development compared with similar training with an intake of 0.8 grams of protein per kilogram of body weight per day (5.) However, it is important to note that there is little good evidence that the very high protein intakes (more than 2 grams per kilogram of body weight per day) typically consumed by strength athletes are beneficial. Moreover, it is possible to obtain this quantity of protein without special supplementation assuming a mixed diet containing sufficient energy is consumed.